CVE-2021-47254

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux6948c6bc17d666663a84c124b3176039e64a58f4 < 38ce329534500bf4ae71f81df6a37a406cf187b4affected
LinuxLinuxb568ed385a18c0ddbe41862b69088b636550a04f < 92869945cc5b78ee8a1ef90336fe070893e3458aaffected
LinuxLinux762bb3528249604bc680a9df635e8995740176de < 0364742decb0f02bc183404868b82896f7992595affected
LinuxLinuxbac8520892812dada1ac93f27d96317470d24b1f < 094bf5670e762afa243d2c41a5c4ab71c7447bf4affected
LinuxLinux7881ef3f33bb80f459ea6020d1e021fc524a6348 < 86fd5b27db743a0ce0cc245e3a34813b2aa6ec1daffected
LinuxLinux7881ef3f33bb80f459ea6020d1e021fc524a6348 < a61156314b66456ab6a291ed5deba1ebd002ab3caffected
LinuxLinux7881ef3f33bb80f459ea6020d1e021fc524a6348 < e87ef30fe73e7e10d2c85bdcc778dcec24dca553affected
LinuxLinux7881ef3f33bb80f459ea6020d1e021fc524a6348 < 1ab19c5de4c537ec0d9b21020395a5b5a6c059b2affected
LinuxLinux1e7a416fb765c9072479dc424780c0937ba99270affected
LinuxLinuxdcbdbe13796ffa561510d2686a6318564e728bbdaffected
LinuxLinux4.4.181 < 4.4.274affected
LinuxLinux4.9.180 < 4.9.274affected
LinuxLinux4.14.123 < 4.14.238affected
LinuxLinux4.19.47 < 4.19.196affected
LinuxLinux5.0.20 < 5.1affected
LinuxLinux5.1.6 < 5.2affected
LinuxLinux5.2affected
LinuxLinux0 < 5.2unaffected
LinuxLinux4.4.274 <= 4.4.*unaffected
LinuxLinux4.9.274 <= 4.9.*unaffected
LinuxLinux4.14.238 <= 4.14.*unaffected
LinuxLinux4.19.196 <= 4.19.*unaffected
LinuxLinux5.4.127 <= 5.4.*unaffected
LinuxLinux5.10.45 <= 5.10.*unaffected
LinuxLinux5.12.12 <= 5.12.*unaffected
LinuxLinux5.13 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

CVE Program Container

Additional References

References