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2025-02-26af_unix: Fix memory leak in unix_dgram_sendmsg()Adrian Huang
After running the 'sendmsg02' program of Linux Test Project (LTP), kmemleak reports the following memory leak: # cat /sys/kernel/debug/kmemleak unreferenced object 0xffff888243866800 (size 2048): comm "sendmsg02", pid 67, jiffies 4294903166 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 5e 00 00 00 00 00 00 00 ........^....... 01 00 07 40 00 00 00 00 00 00 00 00 00 00 00 00 ...@............ backtrace (crc 7e96a3f2): kmemleak_alloc+0x56/0x90 kmem_cache_alloc_noprof+0x209/0x450 sk_prot_alloc.constprop.0+0x60/0x160 sk_alloc+0x32/0xc0 unix_create1+0x67/0x2b0 unix_create+0x47/0xa0 __sock_create+0x12e/0x200 __sys_socket+0x6d/0x100 __x64_sys_socket+0x1b/0x30 x64_sys_call+0x7e1/0x2140 do_syscall_64+0x54/0x110 entry_SYSCALL_64_after_hwframe+0x76/0x7e Commit 689c398885cc ("af_unix: Defer sock_put() to clean up path in unix_dgram_sendmsg().") defers sock_put() in the error handling path. However, it fails to account for the condition 'msg->msg_namelen != 0', resulting in a memory leak when the code jumps to the 'lookup' label. Fix issue by calling sock_put() if 'msg->msg_namelen != 0' is met. Fixes: 689c398885cc ("af_unix: Defer sock_put() to clean up path in unix_dgram_sendmsg().") Signed-off-by: Adrian Huang <ahuang12@lenovo.com> Acked-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250225021457.1824-1-ahuang12@lenovo.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20af_unix: Use consume_skb() in connect() and sendmsg().Kuniyuki Iwashima
This is based on Donald Hunter's patch. These functions could fail for various reasons, sometimes triggering kfree_skb(). * unix_stream_connect() : connect() * unix_stream_sendmsg() : sendmsg() * queue_oob() : sendmsg(MSG_OOB) * unix_dgram_sendmsg() : sendmsg() Such kfree_skb() is tied to the errno of connect() and sendmsg(), and we need not define skb drop reasons. Let's use consume_skb() not to churn kfree_skb() events. Link: https://lore.kernel.org/netdev/eb30b164-7f86-46bf-a5d3-0f8bda5e9398@redhat.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250116053441.5758-10-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20af_unix: Reuse out_pipe label in unix_stream_sendmsg().Kuniyuki Iwashima
This is a follow-up of commit d460b04bc452 ("af_unix: Clean up error paths in unix_stream_sendmsg()."). If we initialise skb with NULL in unix_stream_sendmsg(), we can reuse the existing out_pipe label for the SEND_SHUTDOWN check. Let's rename it and adjust the existing label as out_pipe_lock. While at it, size and data_len are moved to the while loop scope. Suggested-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250116053441.5758-9-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20af_unix: Set drop reason in unix_dgram_disconnected().Kuniyuki Iwashima
unix_dgram_disconnected() is called from two places: 1. when a connect()ed socket dis-connect()s or re-connect()s to another socket 2. when sendmsg() fails because the peer socket that the client has connect()ed to has been close()d Then, the client's recv queue is purged to remove all messages from the old peer socket. Let's define a new drop reason for that case. # echo 1 > /sys/kernel/tracing/events/skb/kfree_skb/enable # python3 >>> from socket import * >>> >>> # s1 has a message from s2 >>> s1, s2 = socketpair(AF_UNIX, SOCK_DGRAM) >>> s2.send(b'hello world') >>> >>> # re-connect() drops the message from s2 >>> s3 = socket(AF_UNIX, SOCK_DGRAM) >>> s3.bind('') >>> s1.connect(s3.getsockname()) # cat /sys/kernel/tracing/trace_pipe python3-250 ... kfree_skb: ... location=skb_queue_purge_reason+0xdc/0x110 reason: UNIX_DISCONNECT Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250116053441.5758-8-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20af_unix: Set drop reason in unix_stream_read_skb().Kuniyuki Iwashima
unix_stream_read_skb() is called when BPF SOCKMAP reads some data from a socket in the map. SOCKMAP does not support MSG_OOB, and reading OOB results in a drop. Let's set drop reasons respectively. * SOCKET_CLOSE : the socket in SOCKMAP was close()d * UNIX_SKIP_OOB : OOB was read from the socket in SOCKMAP Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250116053441.5758-7-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20af_unix: Set drop reason in manage_oob().Kuniyuki Iwashima
AF_UNIX SOCK_STREAM socket supports MSG_OOB. When OOB data is sent to a socket, recv() will break at that point. If the next recv() does not have MSG_OOB, the normal data following the OOB data is returned. Then, the OOB skb is dropped. Let's define a new drop reason for that case in manage_oob(). # echo 1 > /sys/kernel/tracing/events/skb/kfree_skb/enable # python3 >>> from socket import * >>> s1, s2 = socketpair(AF_UNIX) >>> s1.send(b'a', MSG_OOB) >>> s1.send(b'b') >>> s2.recv(2) b'b' # cat /sys/kernel/tracing/trace_pipe ... python3-223 ... kfree_skb: ... location=unix_stream_read_generic+0x59e/0xc20 reason: UNIX_SKIP_OOB Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250116053441.5758-6-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20af_unix: Set drop reason in __unix_gc().Kuniyuki Iwashima
Inflight file descriptors by SCM_RIGHTS hold references to the struct file. AF_UNIX sockets could hold references to each other, forming reference cycles. Once such sockets are close()d without the fd recv()ed, they will be unaccessible from userspace but remain in kernel. __unix_gc() garbage-collects skb with the dead file descriptors and frees them by __skb_queue_purge(). Let's set SKB_DROP_REASON_SOCKET_CLOSE there. # echo 1 > /sys/kernel/tracing/events/skb/kfree_skb/enable # python3 >>> from socket import * >>> from array import array >>> >>> # Create a reference cycle >>> s1 = socket(AF_UNIX, SOCK_DGRAM) >>> s1.bind('') >>> s1.sendmsg([b"nop"], [(SOL_SOCKET, SCM_RIGHTS, array("i", [s1.fileno()]))], 0, s1.getsockname()) >>> s1.close() >>> >>> # Trigger GC >>> s2 = socket(AF_UNIX) >>> s2.close() # cat /sys/kernel/tracing/trace_pipe ... kworker/u16:2-42 ... kfree_skb: ... location=__unix_gc+0x4ad/0x580 reason: SOCKET_CLOSE Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250116053441.5758-5-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20af_unix: Set drop reason in unix_sock_destructor().Kuniyuki Iwashima
unix_sock_destructor() is called as sk->sk_destruct() just before the socket is actually freed. Let's use SKB_DROP_REASON_SOCKET_CLOSE for skb_queue_purge(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250116053441.5758-4-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20af_unix: Set drop reason in unix_release_sock().Kuniyuki Iwashima
unix_release_sock() is called when the last refcnt of struct file is released. Let's define a new drop reason SKB_DROP_REASON_SOCKET_CLOSE and set it for kfree_skb() in unix_release_sock(). # echo 1 > /sys/kernel/tracing/events/skb/kfree_skb/enable # python3 >>> from socket import * >>> s1, s2 = socketpair(AF_UNIX) >>> s1.send(b'hello world') >>> s2.close() # cat /sys/kernel/tracing/trace_pipe ... python3-280 ... kfree_skb: ... protocol=0 location=unix_release_sock+0x260/0x420 reason: SOCKET_CLOSE To be precise, unix_release_sock() is also called for a new child socket in unix_stream_connect() when something fails, but the new sk does not have skb in the recv queue then and no event is logged. Note that only tcp_inbound_ao_hash() uses a similar drop reason, SKB_DROP_REASON_TCP_CLOSE, and this can be generalised later. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250116053441.5758-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-19af_unix: Add a prompt to CONFIG_AF_UNIX_OOBFlorent Revest
This makes it possible to disable the MSG_OOB support in .config. Signed-off-by: Florent Revest <revest@chromium.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20241218143334.1507465-1-revest@chromium.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-17af_unix: Remove unix_our_peer().Kuniyuki Iwashima
unix_our_peer() is used only in unix_may_send(). Let's inline it in unix_may_send(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-12-17af_unix: Clean up error paths in unix_dgram_sendmsg().Kuniyuki Iwashima
The error path is complicated in unix_dgram_sendmsg() because there are two timings when other could be non-NULL: when it's fetched from unix_peer_get() and when it's looked up by unix_find_other(). Let's move unix_peer_get() to the else branch for unix_find_other() and clean up the error paths. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-12-17af_unix: Clean up SOCK_DEAD error paths in unix_dgram_sendmsg().Kuniyuki Iwashima
When other has SOCK_DEAD in unix_dgram_sendmsg(), we hold unix_state_lock() for the sender socket first. However, we do not need it for sk->sk_type. Let's move the lock down a bit. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-12-17af_unix: Defer sock_put() to clean up path in unix_dgram_sendmsg().Kuniyuki Iwashima
When other has SOCK_DEAD in unix_dgram_sendmsg(), we call sock_put() for it first and then set NULL to other before jumping to the error path. This is to skip sock_put() in the error path. Let's not set NULL to other and defer the sock_put() to the error path to clean up the labels later. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-12-17af_unix: Split restart label in unix_dgram_sendmsg().Kuniyuki Iwashima
There are two paths jumping to the restart label in unix_dgram_sendmsg(). One requires another lookup and sk_filter(), but the other doesn't. Let's split the label to make each flow more straightforward. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-12-17af_unix: Use msg->{msg_name,msg_namelen} in unix_dgram_sendmsg().Kuniyuki Iwashima
In unix_dgram_sendmsg(), we use a local variable sunaddr pointing NULL or msg->msg_name based on msg->msg_namelen. Let's remove sunaddr and simplify the usage. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-12-17af_unix: Move !sunaddr case in unix_dgram_sendmsg().Kuniyuki Iwashima
When other is NULL in unix_dgram_sendmsg(), we check if sunaddr is NULL before looking up a receiver socket. There are three paths going through the check, but it's always false for 2 out of the 3 paths: the first socket lookup and the second 'goto restart'. The condition can be true for the first 'goto restart' only when SOCK_DEAD is flagged for the socket found with msg->msg_name. Let's move the check to the single appropriate path. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-12-17af_unix: Set error only when needed in unix_dgram_sendmsg().Kuniyuki Iwashima
We will introduce skb drop reason for AF_UNIX, then we need to set an errno and a drop reason for each path. Let's set an error only when it's needed in unix_dgram_sendmsg(). Then, we need not (re)set 0 to err. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-12-17af_unix: Clean up error paths in unix_stream_sendmsg().Kuniyuki Iwashima
If we move send_sig() to the SEND_SHUTDOWN check before the while loop, then we can reuse the same kfree_skb() after the pipe_err_free label. Let's gather the scattered kfree_skb()s in error paths. While at it, some style issues are fixed, and the pipe_err_free label is renamed to out_pipe to match other label names. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-12-17af_unix: Set error only when needed in unix_stream_sendmsg().Kuniyuki Iwashima
We will introduce skb drop reason for AF_UNIX, then we need to set an errno and a drop reason for each path. Let's set an error only when it's needed in unix_stream_sendmsg(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-12-17af_unix: Clean up error paths in unix_stream_connect().Kuniyuki Iwashima
The label order is weird in unix_stream_connect(), and all NULL checks are unnecessary if reordered. Let's clean up the error paths to make it easy to set a drop reason for each path. While at it, a comment with the old style is updated. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-12-17af_unix: Set error only when needed in unix_stream_connect().Kuniyuki Iwashima
We will introduce skb drop reason for AF_UNIX, then we need to set an errno and a drop reason for each path. Let's set an error only when it's needed in unix_stream_connect(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-12-11splice: do not checksum AF_UNIX socketsFrederik Deweerdt
When `skb_splice_from_iter` was introduced, it inadvertently added checksumming for AF_UNIX sockets. This resulted in significant slowdowns, for example when using sendfile over unix sockets. Using the test code in [1] in my test setup (2G single core qemu), the client receives a 1000M file in: - without the patch: 1482ms (+/- 36ms) - with the patch: 652.5ms (+/- 22.9ms) This commit addresses the issue by marking checksumming as unnecessary in `unix_stream_sendmsg` Cc: stable@vger.kernel.org Signed-off-by: Frederik Deweerdt <deweerdt.lkml@gmail.com> Fixes: 2e910b95329c ("net: Add a function to splice pages into an skbuff for MSG_SPLICE_PAGES") Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Joe Damato <jdamato@fastly.com> Link: https://patch.msgid.link/Z1fMaHkRf8cfubuE@xiberoa Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-09af_unix: Don't return OOB skb in manage_oob().Kuniyuki Iwashima
syzbot reported use-after-free in unix_stream_recv_urg(). [0] The scenario is 1. send(MSG_OOB) 2. recv(MSG_OOB) -> The consumed OOB remains in recv queue 3. send(MSG_OOB) 4. recv() -> manage_oob() returns the next skb of the consumed OOB -> This is also OOB, but unix_sk(sk)->oob_skb is not cleared 5. recv(MSG_OOB) -> unix_sk(sk)->oob_skb is used but already freed The recent commit 8594d9b85c07 ("af_unix: Don't call skb_get() for OOB skb.") uncovered the issue. If the OOB skb is consumed and the next skb is peeked in manage_oob(), we still need to check if the skb is OOB. Let's do so by falling back to the following checks in manage_oob() and add the test case in selftest. Note that we need to add a similar check for SIOCATMARK. [0]: BUG: KASAN: slab-use-after-free in unix_stream_read_actor+0xa6/0xb0 net/unix/af_unix.c:2959 Read of size 4 at addr ffff8880326abcc4 by task syz-executor178/5235 CPU: 0 UID: 0 PID: 5235 Comm: syz-executor178 Not tainted 6.11.0-rc5-syzkaller-00742-gfbdaffe41adc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 unix_stream_read_actor+0xa6/0xb0 net/unix/af_unix.c:2959 unix_stream_recv_urg+0x1df/0x320 net/unix/af_unix.c:2640 unix_stream_read_generic+0x2456/0x2520 net/unix/af_unix.c:2778 unix_stream_recvmsg+0x22b/0x2c0 net/unix/af_unix.c:2996 sock_recvmsg_nosec net/socket.c:1046 [inline] sock_recvmsg+0x22f/0x280 net/socket.c:1068 ____sys_recvmsg+0x1db/0x470 net/socket.c:2816 ___sys_recvmsg net/socket.c:2858 [inline] __sys_recvmsg+0x2f0/0x3e0 net/socket.c:2888 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5360d6b4e9 Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff29b3a458 EFLAGS: 00000246 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 00007fff29b3a638 RCX: 00007f5360d6b4e9 RDX: 0000000000002001 RSI: 0000000020000640 RDI: 0000000000000003 RBP: 00007f5360dde610 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007fff29b3a628 R14: 0000000000000001 R15: 0000000000000001 </TASK> Allocated by task 5235: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:312 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3988 [inline] slab_alloc_node mm/slub.c:4037 [inline] kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4080 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:667 alloc_skb include/linux/skbuff.h:1320 [inline] alloc_skb_with_frags+0xc3/0x770 net/core/skbuff.c:6528 sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2815 sock_alloc_send_skb include/net/sock.h:1778 [inline] queue_oob+0x108/0x680 net/unix/af_unix.c:2198 unix_stream_sendmsg+0xd24/0xf80 net/unix/af_unix.c:2351 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597 ___sys_sendmsg net/socket.c:2651 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2680 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5235: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2252 [inline] slab_free mm/slub.c:4473 [inline] kmem_cache_free+0x145/0x350 mm/slub.c:4548 unix_stream_read_generic+0x1ef6/0x2520 net/unix/af_unix.c:2917 unix_stream_recvmsg+0x22b/0x2c0 net/unix/af_unix.c:2996 sock_recvmsg_nosec net/socket.c:1046 [inline] sock_recvmsg+0x22f/0x280 net/socket.c:1068 __sys_recvfrom+0x256/0x3e0 net/socket.c:2255 __do_sys_recvfrom net/socket.c:2273 [inline] __se_sys_recvfrom net/socket.c:2269 [inline] __x64_sys_recvfrom+0xde/0x100 net/socket.c:2269 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880326abc80 which belongs to the cache skbuff_head_cache of size 240 The buggy address is located 68 bytes inside of freed 240-byte region [ffff8880326abc80, ffff8880326abd70) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x326ab ksm flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: 0xfdffffff(slab) raw: 00fff00000000000 ffff88801eaee780 ffffea0000b7dc80 dead000000000003 raw: 0000000000000000 00000000800c000c 00000001fdffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 4686, tgid 4686 (udevadm), ts 32357469485, free_ts 28829011109 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1493 prep_new_page mm/page_alloc.c:1501 [inline] get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3439 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4695 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page+0x5f/0x120 mm/slub.c:2321 allocate_slab+0x5a/0x2f0 mm/slub.c:2484 new_slab mm/slub.c:2537 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3723 __slab_alloc+0x58/0xa0 mm/slub.c:3813 __slab_alloc_node mm/slub.c:3866 [inline] slab_alloc_node mm/slub.c:4025 [inline] kmem_cache_alloc_node_noprof+0x1fe/0x320 mm/slub.c:4080 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:667 alloc_skb include/linux/skbuff.h:1320 [inline] alloc_uevent_skb+0x74/0x230 lib/kobject_uevent.c:289 uevent_net_broadcast_untagged lib/kobject_uevent.c:326 [inline] kobject_uevent_net_broadcast+0x2fd/0x580 lib/kobject_uevent.c:410 kobject_uevent_env+0x57d/0x8e0 lib/kobject_uevent.c:608 kobject_synth_uevent+0x4ef/0xae0 lib/kobject_uevent.c:207 uevent_store+0x4b/0x70 drivers/base/bus.c:633 kernfs_fop_write_iter+0x3a1/0x500 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa72/0xc90 fs/read_write.c:590 page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1094 [inline] free_unref_page+0xd22/0xea0 mm/page_alloc.c:2612 kasan_depopulate_vmalloc_pte+0x74/0x90 mm/kasan/shadow.c:408 apply_to_pte_range mm/memory.c:2797 [inline] apply_to_pmd_range mm/memory.c:2841 [inline] apply_to_pud_range mm/memory.c:2877 [inline] apply_to_p4d_range mm/memory.c:2913 [inline] __apply_to_page_range+0x8a8/0xe50 mm/memory.c:2947 kasan_release_vmalloc+0x9a/0xb0 mm/kasan/shadow.c:525 purge_vmap_node+0x3e3/0x770 mm/vmalloc.c:2208 __purge_vmap_area_lazy+0x708/0xae0 mm/vmalloc.c:2290 _vm_unmap_aliases+0x79d/0x840 mm/vmalloc.c:2885 change_page_attr_set_clr+0x2fe/0xdb0 arch/x86/mm/pat/set_memory.c:1881 change_page_attr_set arch/x86/mm/pat/set_memory.c:1922 [inline] set_memory_nx+0xf2/0x130 arch/x86/mm/pat/set_memory.c:2110 free_init_pages arch/x86/mm/init.c:924 [inline] free_kernel_image_pages arch/x86/mm/init.c:943 [inline] free_initmem+0x79/0x110 arch/x86/mm/init.c:970 kernel_init+0x31/0x2b0 init/main.c:1476 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Memory state around the buggy address: ffff8880326abb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880326abc00: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc >ffff8880326abc80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880326abd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ffff8880326abd80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb Fixes: 93c99f21db36 ("af_unix: Don't stop recv(MSG_DONTWAIT) if consumed OOB skb is at the head.") Reported-by: syzbot+8811381d455e3e9ec788@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=8811381d455e3e9ec788 Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20240905193240.17565-5-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-09af_unix: Move spin_lock() in manage_oob().Kuniyuki Iwashima
When OOB skb has been already consumed, manage_oob() returns the next skb if exists. In such a case, we need to fall back to the else branch below. Then, we want to keep holding spin_lock(&sk->sk_receive_queue.lock). Let's move it out of if-else branch and add lightweight check before spin_lock() for major use cases without OOB skb. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20240905193240.17565-4-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-09af_unix: Rename unlinked_skb in manage_oob().Kuniyuki Iwashima
When OOB skb has been already consumed, manage_oob() returns the next skb if exists. In such a case, we need to fall back to the else branch below. Then, we need to keep two skbs and free them later with consume_skb() and kfree_skb(). Let's rename unlinked_skb accordingly. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20240905193240.17565-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-09af_unix: Remove single nest in manage_oob().Kuniyuki Iwashima
This is a prep for the later fix. No functional change intended. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20240905193240.17565-2-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-20af_unix: Don't call skb_get() for OOB skb.Kuniyuki Iwashima
Since introduced, OOB skb holds an additional reference count with no special reason and caused many issues. Also, kfree_skb() and consume_skb() are used to decrement the count, which is confusing. Let's drop the unnecessary skb_get() in queue_oob() and corresponding kfree_skb(), consume_skb(), and skb_unref(). Now unix_sk(sk)->oob_skb is just a pointer to skb in the receive queue, so special handing is no longer needed in GC. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20240816233921.57800-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-17af_unix: Disable MSG_OOB handling for sockets in sockmap/sockhashMichal Luczaj
AF_UNIX socket tracks the most recent OOB packet (in its receive queue) with an `oob_skb` pointer. BPF redirecting does not account for that: when an OOB packet is moved between sockets, `oob_skb` is left outdated. This results in a single skb that may be accessed from two different sockets. Take the easy way out: silently drop MSG_OOB data targeting any socket that is in a sockmap or a sockhash. Note that such silent drop is akin to the fate of redirected skb's scm_fp_list (SCM_RIGHTS, SCM_CREDENTIALS). For symmetry, forbid MSG_OOB in unix_bpf_recvmsg(). Fixes: 314001f0bf92 ("af_unix: Add OOB support") Suggested-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Michal Luczaj <mhal@rbox.co> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Jakub Sitnicki <jakub@cloudflare.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/20240713200218.2140950-2-mhal@rbox.co
2024-07-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. Conflicts: drivers/net/phy/aquantia/aquantia.h 219343755eae ("net: phy: aquantia: add missing include guards") 61578f679378 ("net: phy: aquantia: add support for PHY LEDs") drivers/net/ethernet/wangxun/libwx/wx_hw.c bd07a9817846 ("net: txgbe: remove separate irq request for MSI and INTx") b501d261a5b3 ("net: txgbe: add FDIR ATR support") https://lore.kernel.org/all/20240703112936.483c1975@canb.auug.org.au/ include/linux/mlx5/mlx5_ifc.h 048a403648fc ("net/mlx5: IFC updates for changing max EQs") 99be56171fa9 ("net/mlx5e: SHAMPO, Re-enable HW-GRO") https://lore.kernel.org/all/20240701133951.6926b2e3@canb.auug.org.au/ Adjacent changes: drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c 4130c67cd123 ("wifi: iwlwifi: mvm: check vif for NULL/ERR_PTR before dereference") 3f3126515fbe ("wifi: iwlwifi: mvm: add mvm-specific guard") include/net/mac80211.h 816c6bec09ed ("wifi: mac80211: fix BSS_CHANGED_UNSOL_BCAST_PROBE_RESP") 5a009b42e041 ("wifi: mac80211: track changes in AP's TPE") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-03af_unix: Fix uninit-value in __unix_walk_scc()Shigeru Yoshida
KMSAN reported uninit-value access in __unix_walk_scc() [1]. In the list_for_each_entry_reverse() loop, when the vertex's index equals it's scc_index, the loop uses the variable vertex as a temporary variable that points to a vertex in scc. And when the loop is finished, the variable vertex points to the list head, in this case scc, which is a local variable on the stack (more precisely, it's not even scc and might underflow the call stack of __unix_walk_scc(): container_of(&scc, struct unix_vertex, scc_entry)). However, the variable vertex is used under the label prev_vertex. So if the edge_stack is not empty and the function jumps to the prev_vertex label, the function will access invalid data on the stack. This causes the uninit-value access issue. Fix this by introducing a new temporary variable for the loop. [1] BUG: KMSAN: uninit-value in __unix_walk_scc net/unix/garbage.c:478 [inline] BUG: KMSAN: uninit-value in unix_walk_scc net/unix/garbage.c:526 [inline] BUG: KMSAN: uninit-value in __unix_gc+0x2589/0x3c20 net/unix/garbage.c:584 __unix_walk_scc net/unix/garbage.c:478 [inline] unix_walk_scc net/unix/garbage.c:526 [inline] __unix_gc+0x2589/0x3c20 net/unix/garbage.c:584 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xade/0x1bf0 kernel/workqueue.c:3312 worker_thread+0xeb6/0x15b0 kernel/workqueue.c:3393 kthread+0x3c4/0x530 kernel/kthread.c:389 ret_from_fork+0x6e/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Uninit was stored to memory at: unix_walk_scc net/unix/garbage.c:526 [inline] __unix_gc+0x2adf/0x3c20 net/unix/garbage.c:584 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xade/0x1bf0 kernel/workqueue.c:3312 worker_thread+0xeb6/0x15b0 kernel/workqueue.c:3393 kthread+0x3c4/0x530 kernel/kthread.c:389 ret_from_fork+0x6e/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Local variable entries created at: ref_tracker_free+0x48/0xf30 lib/ref_tracker.c:222 netdev_tracker_free include/linux/netdevice.h:4058 [inline] netdev_put include/linux/netdevice.h:4075 [inline] dev_put include/linux/netdevice.h:4101 [inline] update_gid_event_work_handler+0xaa/0x1b0 drivers/infiniband/core/roce_gid_mgmt.c:813 CPU: 1 PID: 12763 Comm: kworker/u8:31 Not tainted 6.10.0-rc4-00217-g35bb670d65fc #32 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 Workqueue: events_unbound __unix_gc Fixes: 3484f063172d ("af_unix: Detect Strongly Connected Components.") Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20240702160428.10153-1-syoshida@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. No conflicts. Adjacent changes: e3f02f32a050 ("ionic: fix kernel panic due to multi-buffer handling") d9c04209990b ("ionic: Mark error paths in the data path as unlikely") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-27af_unix: Fix wrong ioctl(SIOCATMARK) when consumed OOB skb is at the head.Kuniyuki Iwashima
Even if OOB data is recv()ed, ioctl(SIOCATMARK) must return 1 when the OOB skb is at the head of the receive queue and no new OOB data is queued. Without fix: # RUN msg_oob.no_peek.oob ... # msg_oob.c:305:oob:Expected answ[0] (0) == oob_head (1) # oob: Test terminated by assertion # FAIL msg_oob.no_peek.oob not ok 2 msg_oob.no_peek.oob With fix: # RUN msg_oob.no_peek.oob ... # OK msg_oob.no_peek.oob ok 2 msg_oob.no_peek.oob Fixes: 314001f0bf92 ("af_unix: Add OOB support") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-27af_unix: Don't stop recv() at consumed ex-OOB skb.Kuniyuki Iwashima
Currently, recv() is stopped at a consumed OOB skb even if a new OOB skb is queued and we can ignore the old OOB skb. >>> from socket import * >>> c1, c2 = socket(AF_UNIX, SOCK_STREAM) >>> c1.send(b'hellowor', MSG_OOB) 8 >>> c2.recv(1, MSG_OOB) # consume OOB data stays at middle of recvq. b'r' >>> c1.send(b'ld', MSG_OOB) 2 >>> c2.recv(10) # recv() stops at the old consumed OOB b'hellowo' # should be 'hellowol' manage_oob() should not stop recv() at the old consumed OOB skb if there is a new OOB data queued. Note that TCP behaviour is apparently wrong in this test case because we can recv() the same OOB data twice. Without fix: # RUN msg_oob.no_peek.ex_oob_ahead_break ... # msg_oob.c:138:ex_oob_ahead_break:AF_UNIX :hellowo # msg_oob.c:139:ex_oob_ahead_break:Expected:hellowol # msg_oob.c:141:ex_oob_ahead_break:Expected ret[0] (7) == expected_len (8) # ex_oob_ahead_break: Test terminated by assertion # FAIL msg_oob.no_peek.ex_oob_ahead_break not ok 11 msg_oob.no_peek.ex_oob_ahead_break With fix: # RUN msg_oob.no_peek.ex_oob_ahead_break ... # msg_oob.c:146:ex_oob_ahead_break:AF_UNIX :hellowol # msg_oob.c:147:ex_oob_ahead_break:TCP :helloworl # OK msg_oob.no_peek.ex_oob_ahead_break ok 11 msg_oob.no_peek.ex_oob_ahead_break Fixes: 314001f0bf92 ("af_unix: Add OOB support") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-27af_unix: Don't stop recv(MSG_DONTWAIT) if consumed OOB skb is at the head.Kuniyuki Iwashima
Let's say a socket send()s "hello" with MSG_OOB and "world" without flags, >>> from socket import * >>> c1, c2 = socketpair(AF_UNIX) >>> c1.send(b'hello', MSG_OOB) 5 >>> c1.send(b'world') 5 and its peer recv()s "hell" and "o". >>> c2.recv(10) b'hell' >>> c2.recv(1, MSG_OOB) b'o' Now the consumed OOB skb stays at the head of recvq to return a correct value for ioctl(SIOCATMARK), which is broken now and fixed by a later patch. Then, if peer issues recv() with MSG_DONTWAIT, manage_oob() returns NULL, so recv() ends up with -EAGAIN. >>> c2.setblocking(False) # This causes -EAGAIN even with available data >>> c2.recv(5) Traceback (most recent call last): File "<stdin>", line 1, in <module> BlockingIOError: [Errno 11] Resource temporarily unavailable However, next recv() will return the following available data, "world". >>> c2.recv(5) b'world' When the consumed OOB skb is at the head of the queue, we need to fetch the next skb to fix the weird behaviour. Note that the issue does not happen without MSG_DONTWAIT because we can retry after manage_oob(). This patch also adds a test case that covers the issue. Without fix: # RUN msg_oob.no_peek.ex_oob_break ... # msg_oob.c:134:ex_oob_break:AF_UNIX :Resource temporarily unavailable # msg_oob.c:135:ex_oob_break:Expected:ld # msg_oob.c:137:ex_oob_break:Expected ret[0] (-1) == expected_len (2) # ex_oob_break: Test terminated by assertion # FAIL msg_oob.no_peek.ex_oob_break not ok 8 msg_oob.no_peek.ex_oob_break With fix: # RUN msg_oob.no_peek.ex_oob_break ... # OK msg_oob.no_peek.ex_oob_break ok 8 msg_oob.no_peek.ex_oob_break Fixes: 314001f0bf92 ("af_unix: Add OOB support") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-27af_unix: Stop recv(MSG_PEEK) at consumed OOB skb.Kuniyuki Iwashima
After consuming OOB data, recv() reading the preceding data must break at the OOB skb regardless of MSG_PEEK. Currently, MSG_PEEK does not stop recv() for AF_UNIX, and the behaviour is not compliant with TCP. >>> from socket import * >>> c1, c2 = socketpair(AF_UNIX) >>> c1.send(b'hello', MSG_OOB) 5 >>> c1.send(b'world') 5 >>> c2.recv(1, MSG_OOB) b'o' >>> c2.recv(9, MSG_PEEK) # This should return b'hell' b'hellworld' # even with enough buffer. Let's fix it by returning NULL for consumed skb and unlinking it only if MSG_PEEK is not specified. This patch also adds test cases that add recv(MSG_PEEK) before each recv(). Without fix: # RUN msg_oob.peek.oob_ahead_break ... # msg_oob.c:134:oob_ahead_break:AF_UNIX :hellworld # msg_oob.c:135:oob_ahead_break:Expected:hell # msg_oob.c:137:oob_ahead_break:Expected ret[0] (9) == expected_len (4) # oob_ahead_break: Test terminated by assertion # FAIL msg_oob.peek.oob_ahead_break not ok 13 msg_oob.peek.oob_ahead_break With fix: # RUN msg_oob.peek.oob_ahead_break ... # OK msg_oob.peek.oob_ahead_break ok 13 msg_oob.peek.oob_ahead_break Fixes: 314001f0bf92 ("af_unix: Add OOB support") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-25af_unix: Don't use spin_lock_nested() in copy_peercred().Kuniyuki Iwashima
When (AF_UNIX, SOCK_STREAM) socket connect()s to a listening socket, the listener's sk_peer_pid/sk_peer_cred are copied to the client in copy_peercred(). Then, two sk_peer_locks are held there; one is client's and another is listener's. However, the latter is not needed because we hold the listner's unix_state_lock() there and unix_listen() cannot update the cred concurrently. Let's drop the unnecessary spin_lock() and use the bare spin_lock() for the client to protect concurrent read by getsockopt(SO_PEERCRED). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-25af_unix: Remove put_pid()/put_cred() in copy_peercred().Kuniyuki Iwashima
When (AF_UNIX, SOCK_STREAM) socket connect()s to a listening socket, the listener's sk_peer_pid/sk_peer_cred are copied to the client in copy_peercred(). Then, the client's sk_peer_pid and sk_peer_cred are always NULL, so we need not call put_pid() and put_cred() there. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-25af_unix: Set sk_peer_pid/sk_peer_cred locklessly for new socket.Kuniyuki Iwashima
init_peercred() is called in 3 places: 1. socketpair() : both sockets 2. connect() : child socket 3. listen() : listening socket The first two need not hold sk_peer_lock because no one can touch the socket. Let's set cred/pid without holding lock for the two cases and rename the old init_peercred() to update_peercred() to properly reflect the use case. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-25af_unix: Define locking order for U_RECVQ_LOCK_EMBRYO in unix_collect_skb().Kuniyuki Iwashima
While GC is cleaning up cyclic references by SCM_RIGHTS, unix_collect_skb() collects skb in the socket's recvq. If the socket is TCP_LISTEN, we need to collect skb in the embryo's queue. Then, both the listener's recvq lock and the embroy's one are held. The locking is always done in the listener -> embryo order. Let's define it as unix_recvq_lock_cmp_fn() instead of using spin_lock_nested(). Note that the reverse order is defined for consistency. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-25af_unix: Remove U_LOCK_DIAG.Kuniyuki Iwashima
sk_diag_dump_icons() acquires embryo's lock by unix_state_lock_nested() to fetch its peer. The embryo's ->peer is set to NULL only when its parent listener is close()d. Then, unix_release_sock() is called for each embryo after unlinking skb by skb_dequeue(). In sk_diag_dump_icons(), we hold the parent's recvq lock, so we need not acquire unix_state_lock_nested(), and peer is always non-NULL. Let's remove unnecessary unix_state_lock_nested() and non-NULL test for peer. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-25af_unix: Don't acquire unix_state_lock() for sock_i_ino().Kuniyuki Iwashima
sk_diag_dump_peer() and sk_diag_dump() call unix_state_lock() for sock_i_ino() which reads SOCK_INODE(sk->sk_socket)->i_ino, but it's protected by sk->sk_callback_lock. Let's remove unnecessary unix_state_lock(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-25af_unix: Define locking order for U_LOCK_SECOND in unix_stream_connect().Kuniyuki Iwashima
While a SOCK_(STREAM|SEQPACKET) socket connect()s to another, we hold two locks of them by unix_state_lock() and unix_state_lock_nested() in unix_stream_connect(). Before unix_state_lock_nested(), the following is guaranteed by checking sk->sk_state: 1. The first socket is TCP_LISTEN 2. The second socket is not the first one 3. Simultaneous connect() must fail So, the client state can be TCP_CLOSE or TCP_LISTEN or TCP_ESTABLISHED. Let's define the expected states as unix_state_lock_cmp_fn() instead of using unix_state_lock_nested(). Note that 2. is detected by debug_spin_lock_before() and 3. cannot be expressed as lock_cmp_fn. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-25af_unix: Don't retry after unix_state_lock_nested() in unix_stream_connect().Kuniyuki Iwashima
When a SOCK_(STREAM|SEQPACKET) socket connect()s to another one, we need to lock the two sockets to check their states in unix_stream_connect(). We use unix_state_lock() for the server and unix_state_lock_nested() for client with tricky sk->sk_state check to avoid deadlock. The possible deadlock scenario are the following: 1) Self connect() 2) Simultaneous connect() The former is simple, attempt to grab the same lock, and the latter is AB-BA deadlock. After the server's unix_state_lock(), we check the server socket's state, and if it's not TCP_LISTEN, connect() fails with -EINVAL. Then, we avoid the former deadlock by checking the client's state before unix_state_lock_nested(). If its state is not TCP_LISTEN, we can make sure that the client and the server are not identical based on the state. Also, the latter deadlock can be avoided in the same way. Due to the server sk->sk_state requirement, AB-BA deadlock could happen only with TCP_LISTEN sockets. So, if the client's state is TCP_LISTEN, we can give up the second lock to avoid the deadlock. CPU 1 CPU 2 CPU 3 connect(A -> B) connect(B -> A) listen(A) --- --- --- unix_state_lock(B) B->sk_state == TCP_LISTEN READ_ONCE(A->sk_state) == TCP_CLOSE ^^^^^^^^^ ok, will lock A unix_state_lock(A) .--------------' WRITE_ONCE(A->sk_state, TCP_LISTEN) | unix_state_unlock(A) | | unix_state_lock(A) | A->sk_sk_state == TCP_LISTEN | READ_ONCE(B->sk_state) == TCP_LISTEN v ^^^^^^^^^^ unix_state_lock_nested(A) Don't lock B !! Currently, while checking the client's state, we also check if it's TCP_ESTABLISHED, but this is unlikely and can be checked after we know the state is not TCP_CLOSE. Moreover, if it happens after the second lock, we now jump to the restart label, but it's unlikely that the server is not found during the retry, so the jump is mostly to revist the client state check. Let's remove the retry logic and check the state against TCP_CLOSE first. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-25af_unix: Define locking order for U_LOCK_SECOND in unix_state_double_lock().Kuniyuki Iwashima
unix_dgram_connect() and unix_dgram_{send,recv}msg() lock the socket and peer in ascending order of the socket address. Let's define the order as unix_state_lock_cmp_fn() instead of using unix_state_lock_nested(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-25af_unix: Define locking order for unix_table_double_lock().Kuniyuki Iwashima
When created, AF_UNIX socket is put into net->unx.table.buckets[], and the hash is stored in sk->sk_hash. * unbound socket : 0 <= sk_hash <= UNIX_HASH_MOD When bind() is called, the socket could be moved to another bucket. * pathname socket : 0 <= sk_hash <= UNIX_HASH_MOD * abstract socket : UNIX_HASH_MOD + 1 <= sk_hash <= UNIX_HASH_MOD * 2 + 1 Then, we call unix_table_double_lock() which locks a single bucket or two. Let's define the order as unix_table_lock_cmp_fn() instead of using spin_lock_nested(). The locking is always done in ascending order of sk->sk_hash, which is the index of buckets/locks array allocated by kvmalloc_array(). sk_hash_A < sk_hash_B <=> &locks[sk_hash_A].dep_map < &locks[sk_hash_B].dep_map So, the relation of two sk->sk_hash can be derived from the addresses of dep_map in the array of locks. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-06-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. No conflicts, no adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-13af_unix: Read with MSG_PEEK loops if the first unread byte is OOBRao Shoaib
Read with MSG_PEEK flag loops if the first byte to read is an OOB byte. commit 22dd70eb2c3d ("af_unix: Don't peek OOB data without MSG_OOB.") addresses the loop issue but does not address the issue that no data beyond OOB byte can be read. >>> from socket import * >>> c1, c2 = socketpair(AF_UNIX, SOCK_STREAM) >>> c1.send(b'a', MSG_OOB) 1 >>> c1.send(b'b') 1 >>> c2.recv(1, MSG_PEEK | MSG_DONTWAIT) b'b' >>> from socket import * >>> c1, c2 = socketpair(AF_UNIX, SOCK_STREAM) >>> c2.setsockopt(SOL_SOCKET, SO_OOBINLINE, 1) >>> c1.send(b'a', MSG_OOB) 1 >>> c1.send(b'b') 1 >>> c2.recv(1, MSG_PEEK | MSG_DONTWAIT) b'a' >>> c2.recv(1, MSG_PEEK | MSG_DONTWAIT) b'a' >>> c2.recv(1, MSG_DONTWAIT) b'a' >>> c2.recv(1, MSG_PEEK | MSG_DONTWAIT) b'b' >>> Fixes: 314001f0bf92 ("af_unix: Add OOB support") Signed-off-by: Rao Shoaib <Rao.Shoaib@oracle.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240611084639.2248934-1-Rao.Shoaib@oracle.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. No conflicts. Adjacent changes: drivers/net/ethernet/pensando/ionic/ionic_txrx.c d9c04209990b ("ionic: Mark error paths in the data path as unlikely") 491aee894a08 ("ionic: fix kernel panic in XDP_TX action") net/ipv6/ip6_fib.c b4cb4a1391dc ("net: use unrcu_pointer() helper") b01e1c030770 ("ipv6: fix possible race in __fib6_drop_pcpu_from()") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-06af_unix: Annotate data-race of sk->sk_shutdown in sk_diag_fill().Kuniyuki Iwashima
While dumping sockets via UNIX_DIAG, we do not hold unix_state_lock(). Let's use READ_ONCE() to read sk->sk_shutdown. Fixes: e4e541a84863 ("sock-diag: Report shutdown for inet and unix sockets (v2)") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>