CVE-2021-47117

Summary

In the Linux kernel, the following vulnerability has been resolved:

ext4: fix bug on in ext4_es_cache_extent as ext4_split_extent_at failed

We got follow bug_on when run fsstress with injecting IO fault: [130747.323114] kernel BUG at fs/ext4/extents_status.c:762! [130747.323117] Internal error: Oops - BUG: 0 [#1] SMP …… [130747.334329] Call trace: [130747.334553] ext4_es_cache_extent+0x150/0x168 [ext4] [130747.334975] ext4_cache_extents+0x64/0xe8 [ext4] [130747.335368] ext4_find_extent+0x300/0x330 [ext4] [130747.335759] ext4_ext_map_blocks+0x74/0x1178 [ext4] [130747.336179] ext4_map_blocks+0x2f4/0x5f0 [ext4] [130747.336567] ext4_mpage_readpages+0x4a8/0x7a8 [ext4] [130747.336995] ext4_readpage+0x54/0x100 [ext4] [130747.337359] generic_file_buffered_read+0x410/0xae8 [130747.337767] generic_file_read_iter+0x114/0x190 [130747.338152] ext4_file_read_iter+0x5c/0x140 [ext4] [130747.338556] __vfs_read+0x11c/0x188 [130747.338851] vfs_read+0x94/0x150 [130747.339110] ksys_read+0x74/0xf0

This patch's modification is according to Jan Kara's suggestion in: https://patchwork.ozlabs.org/project/linux-ext4/patch/20210428085158.3728201-1-yebin10@huawei.com/ "I see. Now I understand your patch. Honestly, seeing how fragile is trying to fix extent tree after split has failed in the middle, I would probably go even further and make sure we fix the tree properly in case of ENOSPC and EDQUOT (those are easily user triggerable). Anything else indicates a HW problem or fs corruption so I'd rather leave the extent tree as is and don't try to fix it (which also means we will not create overlapping extents)."

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxadb2355104b2109e06ba5276485d187d023b2fd2 < e33bafad30d34cfa5e9787cb099cab05e2677fcbaffected
LinuxLinuxadb2355104b2109e06ba5276485d187d023b2fd2 < 5b3a9a2be59478b013a430ac57b0f3d65471b071affected
LinuxLinuxadb2355104b2109e06ba5276485d187d023b2fd2 < d8116743ef5432336289256b2f7c117299213eb9affected
LinuxLinuxadb2355104b2109e06ba5276485d187d023b2fd2 < 569496aa3776eea1ff0d49d0174ac1b7e861e107affected
LinuxLinuxadb2355104b2109e06ba5276485d187d023b2fd2 < 920697b004e49cb026e2e15fe91be065bf0741b7affected
LinuxLinuxadb2355104b2109e06ba5276485d187d023b2fd2 < d3b668b96ad3192c0581a248ae2f596cd054792aaffected
LinuxLinuxadb2355104b2109e06ba5276485d187d023b2fd2 < 48105dc98c9ca35af418746277b087cb2bc6df7caffected
LinuxLinuxadb2355104b2109e06ba5276485d187d023b2fd2 < 082cd4ec240b8734a82a89ffb890216ac98fec68affected
LinuxLinux3.9affected
LinuxLinux0 < 3.9unaffected
LinuxLinux4.4.272 <= 4.4.*unaffected
LinuxLinux4.9.272 <= 4.9.*unaffected
LinuxLinux4.14.236 <= 4.14.*unaffected
LinuxLinux4.19.194 <= 4.19.*unaffected
LinuxLinux5.4.125 <= 5.4.*unaffected
LinuxLinux5.10.43 <= 5.10.*unaffected
LinuxLinux5.12.10 <= 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