CVE-2021-47254

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.

• linux linux kernel (>= 4.4.181 < 4.4.274) • linux linux kernel (>= 4.9.180 < 4.9.274) • linux linux kernel (>= 4.14.123 < 4.14.238) • linux linux kernel (>= 4.19.47 < 4.19.196) • linux linux kernel (>= 5.0.20 < 5.1) • linux linux kernel (>= 5.1.6 < 5.4.127) • linux linux kernel (>= 5.5 < 5.10.45) • linux linux kernel (>= 5.11 < 5.12.12) • linux linux kernel 5.13