lwn.git/fs/ksmbd/smb2misc.c, branch alabaster

ksmbd: prevent out of bound read for SMB2_TREE_CONNNECT

2022-08-01T04:14:32+00:00

if Status is not 0 and PathLength is long, smb_strndup_from_utf16 could make out of bound read in smb2_tree_connnect. This bug can lead an oops looking something like: [ 1553.882047] BUG: KASAN: slab-out-of-bounds in smb_strndup_from_utf16+0x469/0x4c0 [ksmbd] [ 1553.882064] Read of size 2 at addr ffff88802c4eda04 by task kworker/0:2/42805 ... [ 1553.882095] Call Trace: [ 1553.882098] [ 1553.882101] dump_stack_lvl+0x49/0x5f [ 1553.882107] print_report.cold+0x5e/0x5cf [ 1553.882112] ? smb_strndup_from_utf16+0x469/0x4c0 [ksmbd] [ 1553.882122] kasan_report+0xaa/0x120 [ 1553.882128] ? smb_strndup_from_utf16+0x469/0x4c0 [ksmbd] [ 1553.882139] __asan_report_load_n_noabort+0xf/0x20 [ 1553.882143] smb_strndup_from_utf16+0x469/0x4c0 [ksmbd] [ 1553.882155] ? smb_strtoUTF16+0x3b0/0x3b0 [ksmbd] [ 1553.882166] ? __kmalloc_node+0x185/0x430 [ 1553.882171] smb2_tree_connect+0x140/0xab0 [ksmbd] [ 1553.882185] handle_ksmbd_work+0x30e/0x1020 [ksmbd] [ 1553.882197] process_one_work+0x778/0x11c0 [ 1553.882201] ? _raw_spin_lock_irq+0x8e/0xe0 [ 1553.882206] worker_thread+0x544/0x1180 [ 1553.882209] ? __cpuidle_text_end+0x4/0x4 [ 1553.882214] kthread+0x282/0x320 [ 1553.882218] ? process_one_work+0x11c0/0x11c0 [ 1553.882221] ? kthread_complete_and_exit+0x30/0x30 [ 1553.882225] ret_from_fork+0x1f/0x30 [ 1553.882231] There is no need to check error request validation in server. This check allow invalid requests not to validate message. Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-17818 Signed-off-by: Hyunchul Lee Acked-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: prevent out of bound read for SMB2_WRITE

2022-08-01T04:14:32+00:00

OOB read memory can be written to a file, if DataOffset is 0 and Length is too large in SMB2_WRITE request of compound request. To prevent this, when checking the length of the data area of SMB2_WRITE in smb2_get_data_area_len(), let the minimum of DataOffset be the size of SMB2 header + the size of SMB2_WRITE header. This bug can lead an oops looking something like: [ 798.008715] BUG: KASAN: slab-out-of-bounds in copy_page_from_iter_atomic+0xd3d/0x14b0 [ 798.008724] Read of size 252 at addr ffff88800f863e90 by task kworker/0:2/2859 ... [ 798.008754] Call Trace: [ 798.008756] [ 798.008759] dump_stack_lvl+0x49/0x5f [ 798.008764] print_report.cold+0x5e/0x5cf [ 798.008768] ? __filemap_get_folio+0x285/0x6d0 [ 798.008774] ? copy_page_from_iter_atomic+0xd3d/0x14b0 [ 798.008777] kasan_report+0xaa/0x120 [ 798.008781] ? copy_page_from_iter_atomic+0xd3d/0x14b0 [ 798.008784] kasan_check_range+0x100/0x1e0 [ 798.008788] memcpy+0x24/0x60 [ 798.008792] copy_page_from_iter_atomic+0xd3d/0x14b0 [ 798.008795] ? pagecache_get_page+0x53/0x160 [ 798.008799] ? iov_iter_get_pages_alloc+0x1590/0x1590 [ 798.008803] ? ext4_write_begin+0xfc0/0xfc0 [ 798.008807] ? current_time+0x72/0x210 [ 798.008811] generic_perform_write+0x2c8/0x530 [ 798.008816] ? filemap_fdatawrite_wbc+0x180/0x180 [ 798.008820] ? down_write+0xb4/0x120 [ 798.008824] ? down_write_killable+0x130/0x130 [ 798.008829] ext4_buffered_write_iter+0x137/0x2c0 [ 798.008833] ext4_file_write_iter+0x40b/0x1490 [ 798.008837] ? __fsnotify_parent+0x275/0xb20 [ 798.008842] ? __fsnotify_update_child_dentry_flags+0x2c0/0x2c0 [ 798.008846] ? ext4_buffered_write_iter+0x2c0/0x2c0 [ 798.008851] __kernel_write+0x3a1/0xa70 [ 798.008855] ? __x64_sys_preadv2+0x160/0x160 [ 798.008860] ? security_file_permission+0x4a/0xa0 [ 798.008865] kernel_write+0xbb/0x360 [ 798.008869] ksmbd_vfs_write+0x27e/0xb90 [ksmbd] [ 798.008881] ? ksmbd_vfs_read+0x830/0x830 [ksmbd] [ 798.008892] ? _raw_read_unlock+0x2a/0x50 [ 798.008896] smb2_write+0xb45/0x14e0 [ksmbd] [ 798.008909] ? __kasan_check_write+0x14/0x20 [ 798.008912] ? _raw_spin_lock_bh+0xd0/0xe0 [ 798.008916] ? smb2_read+0x15e0/0x15e0 [ksmbd] [ 798.008927] ? memcpy+0x4e/0x60 [ 798.008931] ? _raw_spin_unlock+0x19/0x30 [ 798.008934] ? ksmbd_smb2_check_message+0x16af/0x2350 [ksmbd] [ 798.008946] ? _raw_spin_lock_bh+0xe0/0xe0 [ 798.008950] handle_ksmbd_work+0x30e/0x1020 [ksmbd] [ 798.008962] process_one_work+0x778/0x11c0 [ 798.008966] ? _raw_spin_lock_irq+0x8e/0xe0 [ 798.008970] worker_thread+0x544/0x1180 [ 798.008973] ? __cpuidle_text_end+0x4/0x4 [ 798.008977] kthread+0x282/0x320 [ 798.008982] ? process_one_work+0x11c0/0x11c0 [ 798.008985] ? kthread_complete_and_exit+0x30/0x30 [ 798.008989] ret_from_fork+0x1f/0x30 [ 798.008995] Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-17817 Signed-off-by: Hyunchul Lee Acked-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: fix outstanding credits related bugs

2022-05-21T20:01:43+00:00

outstanding credits must be initialized to 0, because it means the sum of credits consumed by in-flight requests. And outstanding credits must be compared with total credits in smb2_validate_credit_charge(), because total credits are the sum of credits granted by ksmbd. This patch fix the following error, while frametest with Windows clients: Limits exceeding the maximum allowable outstanding requests, given : 128, pending : 8065 Fixes: b589f5db6d4a ("ksmbd: limits exceeding the maximum allowable outstanding requests") Cc: stable@vger.kernel.org Signed-off-by: Hyunchul Lee Reported-by: Yufan Chen Tested-by: Yufan Chen Acked-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: limits exceeding the maximum allowable outstanding requests

2022-01-10T18:44:19+00:00

If the client ignores the CreditResponse received from the server and continues to send the request, ksmbd limits the requests if it exceeds smb2 max credits. Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: move credit charge deduction under processing request

2022-01-10T18:44:19+00:00

Moves the credit charge deduction from total_credits under the processing a request. When repeating smb2 lock request and other command request, there will be a problem that ->total_credits does not decrease. Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: add support for smb2 max credit parameter

2022-01-10T18:44:19+00:00

Add smb2 max credits parameter to adjust maximum credits value to limit number of outstanding requests. Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: switch to use shared definitions where available

2021-11-12T01:22:58+00:00

Acked-by: Namjae Jeon Signed-off-by: Ronnie Sahlberg Signed-off-by: Steve French

ksmbd: remove smb2_buf_length in smb2_hdr

2021-11-12T01:22:58+00:00

To move smb2_hdr to smbfs_common, This patch remove smb2_buf_length variable in smb2_hdr. Also, declare smb2_get_msg function to get smb2 request/response from ->request/response_buf. Cc: Ronnie Sahlberg Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: don't need 8byte alignment for request length in ksmbd_check_message

2021-11-07T04:52:06+00:00

When validating request length in ksmbd_check_message, 8byte alignment is not needed for compound request. It can cause wrong validation of request length. Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org # v5.15 Acked-by: Hyunchul Lee Signed-off-by: Namjae Jeon Signed-off-by: Steve French

ksmbd: use ksmbd_req_buf_next() in ksmbd_smb2_check_message()

2021-11-07T04:52:06+00:00

Use ksmbd_req_buf_next() in ksmbd_smb2_check_message(). Cc: Tom Talpey Cc: Ronnie Sahlberg Cc: Steve French Cc: Hyunchul Lee Acked-by: Namjae Jeon Signed-off-by: Ralph Boehme Signed-off-by: Steve French