| 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-2023-52699: sysv: don't call sb_bread() with pointers_lock held |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| sysv: don't call sb_bread() with pointers_lock held |
| |
| syzbot is reporting sleep in atomic context in SysV filesystem [1], for |
| sb_bread() is called with rw_spinlock held. |
| |
| A "write_lock(&pointers_lock) => read_lock(&pointers_lock) deadlock" bug |
| and a "sb_bread() with write_lock(&pointers_lock)" bug were introduced by |
| "Replace BKL for chain locking with sysvfs-private rwlock" in Linux 2.5.12. |
| |
| Then, "[PATCH] err1-40: sysvfs locking fix" in Linux 2.6.8 fixed the |
| former bug by moving pointers_lock lock to the callers, but instead |
| introduced a "sb_bread() with read_lock(&pointers_lock)" bug (which made |
| this problem easier to hit). |
| |
| Al Viro suggested that why not to do like get_branch()/get_block()/ |
| find_shared() in Minix filesystem does. And doing like that is almost a |
| revert of "[PATCH] err1-40: sysvfs locking fix" except that get_branch() |
| from with find_shared() is called without write_lock(&pointers_lock). |
| |
| The Linux kernel CVE team has assigned CVE-2023-52699 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 4.19.312 with commit 13b33feb2ebddc2b1aa607f553566b18a4af1d76 |
| Fixed in 5.4.274 with commit 1b4fe801b5bedec2b622ddb18e5c9bf26c63d79f |
| Fixed in 5.10.215 with commit 674c1c4229e743070e09db63a23442950ff000d1 |
| Fixed in 5.15.155 with commit fd203d2c671bdee9ab77090ff394d3b71b627927 |
| Fixed in 6.1.86 with commit 53cb1e52c9db618c08335984d1ca80db220ccf09 |
| Fixed in 6.6.27 with commit 89e8524135a3902e7563a5a59b7b5ec1bf4904ac |
| Fixed in 6.8.6 with commit a69224223746ab96d43e5db9d22d136827b7e2d3 |
| Fixed in 6.9 with commit f123dc86388cb669c3d6322702dc441abc35c31e |
| |
| 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-2023-52699 |
| 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/sysv/itree.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/13b33feb2ebddc2b1aa607f553566b18a4af1d76 |
| https://git.kernel.org/stable/c/1b4fe801b5bedec2b622ddb18e5c9bf26c63d79f |
| https://git.kernel.org/stable/c/674c1c4229e743070e09db63a23442950ff000d1 |
| https://git.kernel.org/stable/c/fd203d2c671bdee9ab77090ff394d3b71b627927 |
| https://git.kernel.org/stable/c/53cb1e52c9db618c08335984d1ca80db220ccf09 |
| https://git.kernel.org/stable/c/89e8524135a3902e7563a5a59b7b5ec1bf4904ac |
| https://git.kernel.org/stable/c/a69224223746ab96d43e5db9d22d136827b7e2d3 |
| https://git.kernel.org/stable/c/f123dc86388cb669c3d6322702dc441abc35c31e |
