From: Zhang Xiaoxu zhangxiaoxu5@huawei.com
[ Upstream commit 3e161c2791f8e661eed24a2c624087084d910215 ]
If the MR allocate failed, the MR recovery work not initialized and list not cleared. Then will be warning and UAF when release the MR:
WARNING: CPU: 4 PID: 824 at kernel/workqueue.c:3066 __flush_work.isra.0+0xf7/0x110 CPU: 4 PID: 824 Comm: mount.cifs Not tainted 6.1.0-rc5+ #82 RIP: 0010:__flush_work.isra.0+0xf7/0x110 Call Trace: <TASK> __cancel_work_timer+0x2ba/0x2e0 smbd_destroy+0x4e1/0x990 _smbd_get_connection+0x1cbd/0x2110 smbd_get_connection+0x21/0x40 cifs_get_tcp_session+0x8ef/0xda0 mount_get_conns+0x60/0x750 cifs_mount+0x103/0xd00 cifs_smb3_do_mount+0x1dd/0xcb0 smb3_get_tree+0x1d5/0x300 vfs_get_tree+0x41/0xf0 path_mount+0x9b3/0xdd0 __x64_sys_mount+0x190/0x1d0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0
BUG: KASAN: use-after-free in smbd_destroy+0x4fc/0x990 Read of size 8 at addr ffff88810b156a08 by task mount.cifs/824 CPU: 4 PID: 824 Comm: mount.cifs Tainted: G W 6.1.0-rc5+ #82 Call Trace: dump_stack_lvl+0x34/0x44 print_report+0x171/0x472 kasan_report+0xad/0x130 smbd_destroy+0x4fc/0x990 _smbd_get_connection+0x1cbd/0x2110 smbd_get_connection+0x21/0x40 cifs_get_tcp_session+0x8ef/0xda0 mount_get_conns+0x60/0x750 cifs_mount+0x103/0xd00 cifs_smb3_do_mount+0x1dd/0xcb0 smb3_get_tree+0x1d5/0x300 vfs_get_tree+0x41/0xf0 path_mount+0x9b3/0xdd0 __x64_sys_mount+0x190/0x1d0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0
Allocated by task 824: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 __kasan_kmalloc+0x7a/0x90 _smbd_get_connection+0x1b6f/0x2110 smbd_get_connection+0x21/0x40 cifs_get_tcp_session+0x8ef/0xda0 mount_get_conns+0x60/0x750 cifs_mount+0x103/0xd00 cifs_smb3_do_mount+0x1dd/0xcb0 smb3_get_tree+0x1d5/0x300 vfs_get_tree+0x41/0xf0 path_mount+0x9b3/0xdd0 __x64_sys_mount+0x190/0x1d0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0
Freed by task 824: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_save_free_info+0x2a/0x40 ____kasan_slab_free+0x143/0x1b0 __kmem_cache_free+0xc8/0x330 _smbd_get_connection+0x1c6a/0x2110 smbd_get_connection+0x21/0x40 cifs_get_tcp_session+0x8ef/0xda0 mount_get_conns+0x60/0x750 cifs_mount+0x103/0xd00 cifs_smb3_do_mount+0x1dd/0xcb0 smb3_get_tree+0x1d5/0x300 vfs_get_tree+0x41/0xf0 path_mount+0x9b3/0xdd0 __x64_sys_mount+0x190/0x1d0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0
Let's initialize the MR recovery work before MR allocate to prevent the warning, remove the MRs from the list to prevent the UAF.
Fixes: c7398583340a ("CIFS: SMBD: Implement RDMA memory registration") Acked-by: Paulo Alcantara (SUSE) pc@cjr.nz Reviewed-by: Tom Talpey tom@talpey.com Signed-off-by: Zhang Xiaoxu zhangxiaoxu5@huawei.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/cifs/smbdirect.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c index c93d4ec843beb..bcc611069308a 100644 --- a/fs/cifs/smbdirect.c +++ b/fs/cifs/smbdirect.c @@ -2240,6 +2240,7 @@ static int allocate_mr_list(struct smbd_connection *info) atomic_set(&info->mr_ready_count, 0); atomic_set(&info->mr_used_count, 0); init_waitqueue_head(&info->wait_for_mr_cleanup); + INIT_WORK(&info->mr_recovery_work, smbd_mr_recovery_work); /* Allocate more MRs (2x) than hardware responder_resources */ for (i = 0; i < info->responder_resources * 2; i++) { smbdirect_mr = kzalloc(sizeof(*smbdirect_mr), GFP_KERNEL); @@ -2267,13 +2268,13 @@ static int allocate_mr_list(struct smbd_connection *info) list_add_tail(&smbdirect_mr->list, &info->mr_list); atomic_inc(&info->mr_ready_count); } - INIT_WORK(&info->mr_recovery_work, smbd_mr_recovery_work); return 0;
out: kfree(smbdirect_mr);
list_for_each_entry_safe(smbdirect_mr, tmp, &info->mr_list, list) { + list_del(&smbdirect_mr->list); ib_dereg_mr(smbdirect_mr->mr); kfree(smbdirect_mr->sgl); kfree(smbdirect_mr);