This is a note to let you know that I've just added the patch titled
smb: client: fix use-after-free bug in cifs_debug_data_proc_show()
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
smb-client-fix-use-after-free-bug-in-cifs_debug_data_proc_show.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From d328c09ee9f15ee5a26431f5aad7c9239fa85e62 Mon Sep 17 00:00:00 2001
From: Paulo Alcantara <pc@xxxxxxxxxxxxx>
Date: Tue, 24 Oct 2023 13:49:15 -0300
Subject: smb: client: fix use-after-free bug in cifs_debug_data_proc_show()
From: Paulo Alcantara <pc@xxxxxxxxxxxxx>
commit d328c09ee9f15ee5a26431f5aad7c9239fa85e62 upstream.
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@xxxxxxxxxxxxxxx
Signed-off-by: Paulo Alcantara (SUSE) <pc@xxxxxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/smb/client/cifs_debug.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/fs/smb/client/cifs_debug.c
+++ b/fs/smb/client/cifs_debug.c
@@ -380,6 +380,11 @@ 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) ||
@@ -400,6 +405,7 @@ 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)));
Patches currently in stable-queue which might be from pc@xxxxxxxxxxxxx are
queue-6.1/cifs-spnego-add-in-host_key_len.patch
queue-6.1/cifs-reconnect-helper-should-set-reconnect-for-the-right-channel.patch
queue-6.1/smb3-fix-creating-fifos-when-mounting-with-sfu-mount-option.patch
queue-6.1/cifs-fix-check-of-rc-in-function-generate_smb3signin.patch
queue-6.1/smb-client-fix-use-after-free-bug-in-cifs_debug_data_proc_show.patch
queue-6.1/smb-client-fix-potential-deadlock-when-releasing-mids.patch
