| From bippy-1.2.0 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-2021-47254: gfs2: Fix use-after-free in gfs2_glock_shrink_scan |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| gfs2: Fix use-after-free in gfs2_glock_shrink_scan |
| |
| The GLF_LRU flag is checked under lru_lock in gfs2_glock_remove_from_lru() to |
| remove the glock from the lru list in __gfs2_glock_put(). |
| |
| On the shrink scan path, the same flag is cleared under lru_lock but because |
| of cond_resched_lock(&lru_lock) in gfs2_dispose_glock_lru(), progress on the |
| put side can be made without deleting the glock from the lru list. |
| |
| Keep GLF_LRU across the race window opened by cond_resched_lock(&lru_lock) to |
| ensure correct behavior on both sides - clear GLF_LRU after list_del under |
| lru_lock. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47254 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.4.181 with commit 6948c6bc17d666663a84c124b3176039e64a58f4 and fixed in 4.4.274 with commit 38ce329534500bf4ae71f81df6a37a406cf187b4 |
| Issue introduced in 4.9.180 with commit b568ed385a18c0ddbe41862b69088b636550a04f and fixed in 4.9.274 with commit 92869945cc5b78ee8a1ef90336fe070893e3458a |
| Issue introduced in 4.14.123 with commit 762bb3528249604bc680a9df635e8995740176de and fixed in 4.14.238 with commit 0364742decb0f02bc183404868b82896f7992595 |
| Issue introduced in 4.19.47 with commit bac8520892812dada1ac93f27d96317470d24b1f and fixed in 4.19.196 with commit 094bf5670e762afa243d2c41a5c4ab71c7447bf4 |
| Issue introduced in 5.2 with commit 7881ef3f33bb80f459ea6020d1e021fc524a6348 and fixed in 5.4.127 with commit 86fd5b27db743a0ce0cc245e3a34813b2aa6ec1d |
| Issue introduced in 5.2 with commit 7881ef3f33bb80f459ea6020d1e021fc524a6348 and fixed in 5.10.45 with commit a61156314b66456ab6a291ed5deba1ebd002ab3c |
| Issue introduced in 5.2 with commit 7881ef3f33bb80f459ea6020d1e021fc524a6348 and fixed in 5.12.12 with commit e87ef30fe73e7e10d2c85bdcc778dcec24dca553 |
| Issue introduced in 5.2 with commit 7881ef3f33bb80f459ea6020d1e021fc524a6348 and fixed in 5.13 with commit 1ab19c5de4c537ec0d9b21020395a5b5a6c059b2 |
| Issue introduced in 5.0.20 with commit 1e7a416fb765c9072479dc424780c0937ba99270 |
| Issue introduced in 5.1.6 with commit dcbdbe13796ffa561510d2686a6318564e728bbd |
| |
| 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-2021-47254 |
| 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/gfs2/glock.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/38ce329534500bf4ae71f81df6a37a406cf187b4 |
| https://git.kernel.org/stable/c/92869945cc5b78ee8a1ef90336fe070893e3458a |
| https://git.kernel.org/stable/c/0364742decb0f02bc183404868b82896f7992595 |
| https://git.kernel.org/stable/c/094bf5670e762afa243d2c41a5c4ab71c7447bf4 |
| https://git.kernel.org/stable/c/86fd5b27db743a0ce0cc245e3a34813b2aa6ec1d |
| https://git.kernel.org/stable/c/a61156314b66456ab6a291ed5deba1ebd002ab3c |
| https://git.kernel.org/stable/c/e87ef30fe73e7e10d2c85bdcc778dcec24dca553 |
| https://git.kernel.org/stable/c/1ab19c5de4c537ec0d9b21020395a5b5a6c059b2 |
