| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2022-49281: cifs: fix handlecache and multiuser |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| cifs: fix handlecache and multiuser |
| |
| In multiuser each individual user has their own tcon structure for the |
| share and thus their own handle for a cached directory. |
| When we umount such a share we much make sure to release the pinned down dentry |
| for each such tcon and not just the master tcon. |
| |
| Otherwise we will get nasty warnings on umount that dentries are still in use: |
| [ 3459.590047] BUG: Dentry 00000000115c6f41{i=12000000019d95,n=/} still in use\ |
| (2) [unmount of cifs cifs] |
| ... |
| [ 3459.590492] Call Trace: |
| [ 3459.590500] d_walk+0x61/0x2a0 |
| [ 3459.590518] ? shrink_lock_dentry.part.0+0xe0/0xe0 |
| [ 3459.590526] shrink_dcache_for_umount+0x49/0x110 |
| [ 3459.590535] generic_shutdown_super+0x1a/0x110 |
| [ 3459.590542] kill_anon_super+0x14/0x30 |
| [ 3459.590549] cifs_kill_sb+0xf5/0x104 [cifs] |
| [ 3459.590773] deactivate_locked_super+0x36/0xa0 |
| [ 3459.590782] cleanup_mnt+0x131/0x190 |
| [ 3459.590789] task_work_run+0x5c/0x90 |
| [ 3459.590798] exit_to_user_mode_loop+0x151/0x160 |
| [ 3459.590809] exit_to_user_mode_prepare+0x83/0xd0 |
| [ 3459.590818] syscall_exit_to_user_mode+0x12/0x30 |
| [ 3459.590828] do_syscall_64+0x48/0x90 |
| [ 3459.590833] entry_SYSCALL_64_after_hwframe+0x44/0xae |
| |
| The Linux kernel CVE team has assigned CVE-2022-49281 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.15.33 with commit 2fafbc198613823943c106d1ec9b516da692059f |
| Fixed in 5.16.19 with commit ffa631c4bff59dde59b598011f570e27dfba3515 |
| Fixed in 5.17.2 with commit e71f6a3a1d5c826a30384fec587ca7503ef6bde5 |
| Fixed in 5.18 with commit 47178c7722ac528ea08aa82c3ef9ffa178962d7a |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2022-49281 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| fs/cifs/cifsfs.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/2fafbc198613823943c106d1ec9b516da692059f |
| https://git.kernel.org/stable/c/ffa631c4bff59dde59b598011f570e27dfba3515 |
| https://git.kernel.org/stable/c/e71f6a3a1d5c826a30384fec587ca7503ef6bde5 |
| https://git.kernel.org/stable/c/47178c7722ac528ea08aa82c3ef9ffa178962d7a |
