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authorLinus Torvalds <torvalds@linux-foundation.org>2018-02-06 19:00:42 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-02-06 19:00:42 -0800
commit0dc400f41f0d589a7d4defabdc537ec7e0640039 (patch)
treefbe4455726d97e64eca353ab516e5833940ced21 /kernel
parentcbd7b8a76b79a2ff6112ef2e77031b694843b8a1 (diff)
parent176bfb406d735655f9a69d868a7af0c3da959d51 (diff)
downloadlwn-0dc400f41f0d589a7d4defabdc537ec7e0640039.tar.gz
lwn-0dc400f41f0d589a7d4defabdc537ec7e0640039.zip
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller: 1) Fix error path in netdevsim, from Jakub Kicinski. 2) Default values listed in tcp_wmem and tcp_rmem documentation were inaccurate, from Tonghao Zhang. 3) Fix route leaks in SCTP, both for ipv4 and ipv6. From Alexey Kodanev and Tommi Rantala. 4) Fix "MASK < Y" meant to be "MASK << Y" in xgbe driver, from Wolfram Sang. 5) Use after free in u32_destroy_key(), from Paolo Abeni. 6) Fix two TX issues in be2net driver, from Suredh Reddy. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (25 commits) be2net: Handle transmit completion errors in Lancer be2net: Fix HW stall issue in Lancer RDS: IB: Fix null pointer issue nfp: fix kdoc warnings on nested structures sample/bpf: fix erspan metadata net: erspan: fix erspan config overwrite net: erspan: fix metadata extraction cls_u32: fix use after free in u32_destroy_key() net: amd-xgbe: fix comparison to bitshift when dealing with a mask net: phy: Handle not having GPIO enabled in the kernel ibmvnic: fix empty firmware version and errors cleanup sctp: fix dst refcnt leak in sctp_v4_get_dst sctp: fix dst refcnt leak in sctp_v6_get_dst() dwc-xlgmac: remove Jie Deng as co-maintainer doc: Change the min default value of tcp_wmem/tcp_rmem. samples/bpf: use bpf_set_link_xdp_fd libbpf: add missing SPDX-License-Identifier libbpf: add error reporting in XDP libbpf: add function to setup XDP tools: add netlink.h and if_link.h in tools uapi ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/core.c32
1 files changed, 24 insertions, 8 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 5f35f93dcab2..29ca9208dcfa 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1576,25 +1576,41 @@ int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs,
__u32 __user *prog_ids, u32 cnt)
{
struct bpf_prog **prog;
- u32 i = 0, id;
-
+ unsigned long err = 0;
+ u32 i = 0, *ids;
+ bool nospc;
+
+ /* users of this function are doing:
+ * cnt = bpf_prog_array_length();
+ * if (cnt > 0)
+ * bpf_prog_array_copy_to_user(..., cnt);
+ * so below kcalloc doesn't need extra cnt > 0 check, but
+ * bpf_prog_array_length() releases rcu lock and
+ * prog array could have been swapped with empty or larger array,
+ * so always copy 'cnt' prog_ids to the user.
+ * In a rare race the user will see zero prog_ids
+ */
+ ids = kcalloc(cnt, sizeof(u32), GFP_USER);
+ if (!ids)
+ return -ENOMEM;
rcu_read_lock();
prog = rcu_dereference(progs)->progs;
for (; *prog; prog++) {
if (*prog == &dummy_bpf_prog.prog)
continue;
- id = (*prog)->aux->id;
- if (copy_to_user(prog_ids + i, &id, sizeof(id))) {
- rcu_read_unlock();
- return -EFAULT;
- }
+ ids[i] = (*prog)->aux->id;
if (++i == cnt) {
prog++;
break;
}
}
+ nospc = !!(*prog);
rcu_read_unlock();
- if (*prog)
+ err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
+ kfree(ids);
+ if (err)
+ return -EFAULT;
+ if (nospc)
return -ENOSPC;
return 0;
}