| From bippy-1.1.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2022-49879: ext4: fix BUG_ON() when directory entry has invalid rec_len |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| ext4: fix BUG_ON() when directory entry has invalid rec_len |
| |
| The rec_len field in the directory entry has to be a multiple of 4. A |
| corrupted filesystem image can be used to hit a BUG() in |
| ext4_rec_len_to_disk(), called from make_indexed_dir(). |
| |
| ------------[ cut here ]------------ |
| kernel BUG at fs/ext4/ext4.h:2413! |
| ... |
| RIP: 0010:make_indexed_dir+0x53f/0x5f0 |
| ... |
| Call Trace: |
| <TASK> |
| ? add_dirent_to_buf+0x1b2/0x200 |
| ext4_add_entry+0x36e/0x480 |
| ext4_add_nondir+0x2b/0xc0 |
| ext4_create+0x163/0x200 |
| path_openat+0x635/0xe90 |
| do_filp_open+0xb4/0x160 |
| ? __create_object.isra.0+0x1de/0x3b0 |
| ? _raw_spin_unlock+0x12/0x30 |
| do_sys_openat2+0x91/0x150 |
| __x64_sys_open+0x6c/0xa0 |
| do_syscall_64+0x3c/0x80 |
| entry_SYSCALL_64_after_hwframe+0x46/0xb0 |
| |
| The fix simply adds a call to ext4_check_dir_entry() to validate the |
| directory entry, returning -EFSCORRUPTED if the entry is invalid. |
| |
| The Linux kernel CVE team has assigned CVE-2022-49879 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.4.224 with commit 2fa24d0274fbf913b56ee31f15bc01168669d909 |
| Fixed in 5.10.154 with commit 156451a67b93986fb07c274ef6995ff40766c5ad |
| Fixed in 5.15.78 with commit 999cff2b6ce3b45c08abf793bf55534777421327 |
| Fixed in 6.0.8 with commit ce1ee2c8827fb6493e91acbd50f664cf2a972c3d |
| Fixed in 6.1 with commit 17a0bc9bd697f75cfdf9b378d5eb2d7409c91340 |
| |
| 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-2022-49879 |
| 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/ext4/namei.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/2fa24d0274fbf913b56ee31f15bc01168669d909 |
| https://git.kernel.org/stable/c/156451a67b93986fb07c274ef6995ff40766c5ad |
| https://git.kernel.org/stable/c/999cff2b6ce3b45c08abf793bf55534777421327 |
| https://git.kernel.org/stable/c/ce1ee2c8827fb6493e91acbd50f664cf2a972c3d |
| https://git.kernel.org/stable/c/17a0bc9bd697f75cfdf9b378d5eb2d7409c91340 |
