CVE-2021-47117

ext4: fix bug on in ext4_es_cache_extent as ext4_split_extent_at failed

MEDIUM

5.5

CVSS Score

Published: March 15, 2024 at 08:14 PM UTC

Updated: June 17, 2026 at 04:16 AM UTC

1 product affected across 1 vendorLinux Kernel

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Severity

MEDIUM5.5

Exploit prediction

EPSS 0.2%

SSVC

No known exploit

Description

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/[email protected]/ "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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Linux Kernel · Linux

95%

v < 4.4.2723.9 ≤ v < 4.14.2363.9 ≤ v < 4.19.1943.9 ≤ v < 4.4.2723.9 ≤ v < 4.9.2723.9 ≤ v < 5.10.433.9 ≤ v < 5.12.103.9 ≤ v < 5.133.9 ≤ v < 5.4.1254.10 ≤ v < 4.14.2364.15 ≤ v < 4.19.1944.20 ≤ v < 5.4.1254.5 ≤ v < 4.9.2725.11 ≤ v < 5.12.105.5 ≤ v < 5.10.435.13 rc1 5.13 rc2 5.13 rc3 5.13 rc4adb2355104b2109e06ba5276485d187d023b2fd2

Vendor states this is fixed in 082cd4ec240b8734a82a89ffb890216ac98fec68 (fixed)

Vendor states this is fixed in 48105dc98c9ca35af418746277b087cb2bc6df7c (fixed)

Vendor states this is fixed in 569496aa3776eea1ff0d49d0174ac1b7e861e107 (fixed)

Vendor states this is fixed in 5b3a9a2be59478b013a430ac57b0f3d65471b071 (fixed)

Vendor states this is fixed in 920697b004e49cb026e2e15fe91be065bf0741b7 (fixed)

Vendor states this is fixed in d3b668b96ad3192c0581a248ae2f596cd054792a (fixed)

Vendor states this is fixed in d8116743ef5432336289256b2f7c117299213eb9 (fixed)

Vendor states this is fixed in e33bafad30d34cfa5e9787cb099cab05e2677fcb (fixed)

Vendor states this is fixed in 3.9 (unaffected)

Vendor states this is fixed in 4.14.236 (unaffected)

Vendor states this is fixed in 4.19.194 (unaffected)

Vendor states this is fixed in 4.4.272 (unaffected)