diff options
| author | Paulo Alcantara <pc@manguebit.com> | 2023-03-15 02:32:54 +0300 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2023-03-15 05:07:44 +0300 |
| commit | 396935de145589c8bfe552fa03a5e38604071829 (patch) | |
| tree | 116ae8787bd04ce834bc4c05d78242c5e350a35e /fs/cifs/connect.c | |
| parent | b56bce502f55505a97e381d546ee881928183126 (diff) | |
| download | linux-396935de145589c8bfe552fa03a5e38604071829.tar.xz | |
cifs: fix use-after-free bug in refresh_cache_worker()
The UAF bug occurred because we were putting DFS root sessions in
cifs_umount() while DFS cache refresher was being executed.
Make DFS root sessions have same lifetime as DFS tcons so we can avoid
the use-after-free bug is DFS cache refresher and other places that
require IPCs to get new DFS referrals on. Also, get rid of mount
group handling in DFS cache as we no longer need it.
This fixes below use-after-free bug catched by KASAN
[ 379.946955] BUG: KASAN: use-after-free in __refresh_tcon.isra.0+0x10b/0xc10 [cifs]
[ 379.947642] Read of size 8 at addr ffff888018f57030 by task kworker/u4:3/56
[ 379.948096]
[ 379.948208] CPU: 0 PID: 56 Comm: kworker/u4:3 Not tainted 6.2.0-rc7-lku #23
[ 379.948661] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
rel-1.16.0-0-gd239552-rebuilt.opensuse.org 04/01/2014
[ 379.949368] Workqueue: cifs-dfscache refresh_cache_worker [cifs]
[ 379.949942] Call Trace:
[ 379.950113] <TASK>
[ 379.950260] dump_stack_lvl+0x50/0x67
[ 379.950510] print_report+0x16a/0x48e
[ 379.950759] ? __virt_addr_valid+0xd8/0x160
[ 379.951040] ? __phys_addr+0x41/0x80
[ 379.951285] kasan_report+0xdb/0x110
[ 379.951533] ? __refresh_tcon.isra.0+0x10b/0xc10 [cifs]
[ 379.952056] ? __refresh_tcon.isra.0+0x10b/0xc10 [cifs]
[ 379.952585] __refresh_tcon.isra.0+0x10b/0xc10 [cifs]
[ 379.953096] ? __pfx___refresh_tcon.isra.0+0x10/0x10 [cifs]
[ 379.953637] ? __pfx___mutex_lock+0x10/0x10
[ 379.953915] ? lock_release+0xb6/0x720
[ 379.954167] ? __pfx_lock_acquire+0x10/0x10
[ 379.954443] ? refresh_cache_worker+0x34e/0x6d0 [cifs]
[ 379.954960] ? __pfx_wb_workfn+0x10/0x10
[ 379.955239] refresh_cache_worker+0x4ad/0x6d0 [cifs]
[ 379.955755] ? __pfx_refresh_cache_worker+0x10/0x10 [cifs]
[ 379.956323] ? __pfx_lock_acquired+0x10/0x10
[ 379.956615] ? read_word_at_a_time+0xe/0x20
[ 379.956898] ? lockdep_hardirqs_on_prepare+0x12/0x220
[ 379.957235] process_one_work+0x535/0x990
[ 379.957509] ? __pfx_process_one_work+0x10/0x10
[ 379.957812] ? lock_acquired+0xb7/0x5f0
[ 379.958069] ? __list_add_valid+0x37/0xd0
[ 379.958341] ? __list_add_valid+0x37/0xd0
[ 379.958611] worker_thread+0x8e/0x630
[ 379.958861] ? __pfx_worker_thread+0x10/0x10
[ 379.959148] kthread+0x17d/0x1b0
[ 379.959369] ? __pfx_kthread+0x10/0x10
[ 379.959630] ret_from_fork+0x2c/0x50
[ 379.959879] </TASK>
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Cc: stable@vger.kernel.org # 6.2
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/cifs/connect.c')
| -rw-r--r-- | fs/cifs/connect.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index b96375f137fa..0eceddde7140 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -3408,7 +3408,8 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx) bool isdfs; int rc; - uuid_gen(&mnt_ctx.mount_id); + INIT_LIST_HEAD(&mnt_ctx.dfs_ses_list); + rc = dfs_mount_share(&mnt_ctx, &isdfs); if (rc) goto error; @@ -3428,7 +3429,6 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx) kfree(cifs_sb->prepath); cifs_sb->prepath = ctx->prepath; ctx->prepath = NULL; - uuid_copy(&cifs_sb->dfs_mount_id, &mnt_ctx.mount_id); out: cifs_try_adding_channels(cifs_sb, mnt_ctx.ses); @@ -3440,7 +3440,7 @@ out: return rc; error: - dfs_cache_put_refsrv_sessions(&mnt_ctx.mount_id); + dfs_put_root_smb_sessions(&mnt_ctx.dfs_ses_list); kfree(mnt_ctx.origin_fullpath); kfree(mnt_ctx.leaf_fullpath); cifs_mount_put_conns(&mnt_ctx); @@ -3638,9 +3638,6 @@ cifs_umount(struct cifs_sb_info *cifs_sb) spin_unlock(&cifs_sb->tlink_tree_lock); kfree(cifs_sb->prepath); -#ifdef CONFIG_CIFS_DFS_UPCALL - dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id); -#endif call_rcu(&cifs_sb->rcu, delayed_free); } |