diff options
| author | Paulo Alcantara <pc@manguebit.com> | 2023-10-24 13:49:15 -0300 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2023-10-31 12:38:26 -0500 |
| commit | d328c09ee9f15ee5a26431f5aad7c9239fa85e62 (patch) | |
| tree | b25a773c214714113c19ed133425edbb32bef63f /fs/smb/client/cifs_debug.c | |
| parent | e6322fd177c6885a21dd4609dc5e5c973d1a2eb7 (diff) | |
smb: client: fix use-after-free bug in cifs_debug_data_proc_show()
Skip SMB sessions that are being teared down
(e.g. @ses->ses_status == SES_EXITING) in cifs_debug_data_proc_show()
to avoid use-after-free in @ses.
This fixes the following GPF when reading from /proc/fs/cifs/DebugData
while mounting and umounting
[ 816.251274] general protection fault, probably for non-canonical
address 0x6b6b6b6b6b6b6d81: 0000 [#1] PREEMPT SMP NOPTI
...
[ 816.260138] Call Trace:
[ 816.260329] <TASK>
[ 816.260499] ? die_addr+0x36/0x90
[ 816.260762] ? exc_general_protection+0x1b3/0x410
[ 816.261126] ? asm_exc_general_protection+0x26/0x30
[ 816.261502] ? cifs_debug_tcon+0xbd/0x240 [cifs]
[ 816.261878] ? cifs_debug_tcon+0xab/0x240 [cifs]
[ 816.262249] cifs_debug_data_proc_show+0x516/0xdb0 [cifs]
[ 816.262689] ? seq_read_iter+0x379/0x470
[ 816.262995] seq_read_iter+0x118/0x470
[ 816.263291] proc_reg_read_iter+0x53/0x90
[ 816.263596] ? srso_alias_return_thunk+0x5/0x7f
[ 816.263945] vfs_read+0x201/0x350
[ 816.264211] ksys_read+0x75/0x100
[ 816.264472] do_syscall_64+0x3f/0x90
[ 816.264750] entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[ 816.265135] RIP: 0033:0x7fd5e669d381
Cc: stable@vger.kernel.org
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/smb/client/cifs_debug.c')
| -rw-r--r-- | fs/smb/client/cifs_debug.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/smb/client/cifs_debug.c b/fs/smb/client/cifs_debug.c index 76922fcc4bc6..9a0ccd87468e 100644 --- a/fs/smb/client/cifs_debug.c +++ b/fs/smb/client/cifs_debug.c @@ -452,6 +452,11 @@ skip_rdma: seq_printf(m, "\n\n\tSessions: "); i = 0; list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) { + spin_lock(&ses->ses_lock); + if (ses->ses_status == SES_EXITING) { + spin_unlock(&ses->ses_lock); + continue; + } i++; if ((ses->serverDomain == NULL) || (ses->serverOS == NULL) || @@ -472,6 +477,7 @@ skip_rdma: ses->ses_count, ses->serverOS, ses->serverNOS, ses->capabilities, ses->ses_status); } + spin_unlock(&ses->ses_lock); seq_printf(m, "\n\tSecurity type: %s ", get_security_type_str(server->ops->select_sectype(server, ses->sectype))); |