| 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-2024-42315: exfat: fix potential deadlock on __exfat_get_dentry_set |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| exfat: fix potential deadlock on __exfat_get_dentry_set |
| |
| When accessing a file with more entries than ES_MAX_ENTRY_NUM, the bh-array |
| is allocated in __exfat_get_entry_set. The problem is that the bh-array is |
| allocated with GFP_KERNEL. It does not make sense. In the following cases, |
| a deadlock for sbi->s_lock between the two processes may occur. |
| |
| CPU0 CPU1 |
| ---- ---- |
| kswapd |
| balance_pgdat |
| lock(fs_reclaim) |
| exfat_iterate |
| lock(&sbi->s_lock) |
| exfat_readdir |
| exfat_get_uniname_from_ext_entry |
| exfat_get_dentry_set |
| __exfat_get_dentry_set |
| kmalloc_array |
| ... |
| lock(fs_reclaim) |
| ... |
| evict |
| exfat_evict_inode |
| lock(&sbi->s_lock) |
| |
| To fix this, let's allocate bh-array with GFP_NOFS. |
| |
| The Linux kernel CVE team has assigned CVE-2024-42315 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.10.190 with commit bd3bdb9e0d656f760b11d0c638d35d7f7068144d and fixed in 5.10.232 with commit 632fb232b6bbf8277edcbe9ecd4b4d98ecb122eb |
| Issue introduced in 5.15.150 with commit 92dcd7d6c6068bf4fd35a6f64d606e27d634807e and fixed in 5.15.175 with commit c052f775ee6ccacd3c97e4cf41a2a657e63d4259 |
| Issue introduced in 6.2 with commit a3ff29a95fde16906304455aa8c0bd84eb770258 and fixed in 6.6.44 with commit a7ac198f8dba791e3144c4da48a5a9b95773ee4b |
| Issue introduced in 6.2 with commit a3ff29a95fde16906304455aa8c0bd84eb770258 and fixed in 6.10.3 with commit 1d1970493c289e3f44b9ec847ed26a5dbdf56a62 |
| Issue introduced in 6.2 with commit a3ff29a95fde16906304455aa8c0bd84eb770258 and fixed in 6.11 with commit 89fc548767a2155231128cb98726d6d2ea1256c9 |
| |
| 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-2024-42315 |
| 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/exfat/dir.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/632fb232b6bbf8277edcbe9ecd4b4d98ecb122eb |
| https://git.kernel.org/stable/c/c052f775ee6ccacd3c97e4cf41a2a657e63d4259 |
| https://git.kernel.org/stable/c/cd1c7858641384191ff7033fb1fc65dfcd559c6f |
| https://git.kernel.org/stable/c/a7ac198f8dba791e3144c4da48a5a9b95773ee4b |
| https://git.kernel.org/stable/c/1d1970493c289e3f44b9ec847ed26a5dbdf56a62 |
| https://git.kernel.org/stable/c/89fc548767a2155231128cb98726d6d2ea1256c9 |
