ext4: fix use-after-free read in ext4_find_extent for bigalloc + inline

Description

In the Linux kernel, the following vulnerability has been resolved: ext4: fix use-after-free read in ext4_find_extent for bigalloc + inline Syzbot found the following issue: loop0: detected capacity change from 0 to 2048 EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 without journal. Quota mode: none. ================================================================== BUG: KASAN: use-after-free in ext4_ext_binsearch_idx fs/ext4/extents.c:768 [inline] BUG: KASAN: use-after-free in ext4_find_extent+0x76e/0xd90 fs/ext4/extents.c:931 Read of size 4 at addr ffff888073644750 by task syz-executor420/5067 CPU: 0 PID: 5067 Comm: syz-executor420 Not tainted 6.2.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106 print_address_description+0x74/0x340 mm/kasan/report.c:306 print_report+0x107/0x1f0 mm/kasan/report.c:417 kasan_report+0xcd/0x100 mm/kasan/report.c:517 ext4_ext_binsearch_idx fs/ext4/extents.c:768 [inline] ext4_find_extent+0x76e/0xd90 fs/ext4/extents.c:931 ext4_clu_mapped+0x117/0x970 fs/ext4/extents.c:5809 ext4_insert_delayed_block fs/ext4/inode.c:1696 [inline] ext4_da_map_blocks fs/ext4/inode.c:1806 [inline] ext4_da_get_block_prep+0x9e8/0x13c0 fs/ext4/inode.c:1870 ext4_block_write_begin+0x6a8/0x2290 fs/ext4/inode.c:1098 ext4_da_write_begin+0x539/0x760 fs/ext4/inode.c:3082 generic_perform_write+0x2e4/0x5e0 mm/filemap.c:3772 ext4_buffered_write_iter+0x122/0x3a0 fs/ext4/file.c:285 ext4_file_write_iter+0x1d0/0x18f0 call_write_iter include/linux/fs.h:2186 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x7dc/0xc50 fs/read_write.c:584 ksys_write+0x177/0x2a0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f4b7a9737b9 RSP: 002b:00007ffc5cac3668 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4b7a9737b9 RDX: 00000000175d9003 RSI: 0000000020000200 RDI: 0000000000000004 RBP: 00007f4b7a933050 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000079f R11: 0000000000000246 R12: 00007f4b7a9330e0 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> Above issue is happens when enable bigalloc and inline data feature. As commit 131294c35ed6 fixed delayed allocation bug in ext4_clu_mapped for bigalloc + inline. But it only resolved issue when has inline data, if inline data has been converted to extent(ext4_da_convert_inline_data_to_extent) before writepages, there is no EXT4_STATE_MAY_INLINE_DATA flag. However i_data is still store inline data in this scene. Then will trigger UAF when find extent. To resolve above issue, there is need to add judge "ext4_has_inline_data(inode)" in ext4_clu_mapped().

Timeline

Scores

EPSS (exploitation in 30 days)

0.16% · top 95% of all CVEs (7 Nov 2026)

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.

Affected products

• Linux · Linux

  • affected 1ed1eef0551bebee8e56973ccd0900e3578edfb7 – < 0ce15000dee0ecd6f235f925a327803e2ef489c6
  • affected 6f4200ec76a0d31200c308ec5a71c68df5417004 – < a34f6dcb78c654ab905642c1b4e7e5fbb4f0babe
  • affected 9404839e0c9db5a517ea83c0ca3388b39d105fdf – < 770b0613637f59f3091dda1ff0c23671a5326b9c
  • affected d440d6427a5e3a877c1c259b8d2b216ddb65e185 – < 40566def189c513be2c694681256d7486cc6e368
  • affected 81b915181c630ee1cffa052e52874fe4e1ba91ac – < 96d440bee177669dc0acedca0abd73bae6a9be8b
  • affected 131294c35ed6f777bd4e79d42af13b5c41bf2775 – < 11c87c8df2cae1d6be83c07e59fef0792de73482
  • affected 131294c35ed6f777bd4e79d42af13b5c41bf2775 – < 14da044725a3ab10affa3566d29c15737c0e67a4
  • affected 131294c35ed6f777bd4e79d42af13b5c41bf2775 – < 835659598c67907b98cd2aa57bb951dfaf675c69
  • affected c0c8edbc8abbe8f16d80a1d794d1ba2c12b6f193
  • affected 4.19.270 – < 4.19.271
  • affected 5.4.229 – < 5.4.243
  • affected 5.10.163 – < 5.10.180
  • affected 5.15.87 – < 5.15.111
  • affected 6.1.4 – < 6.1.28
  • affected 6.0.18 – < 6.1

• Linux · Linux

  • affected 6.2
  • unaffected < 6.2
  • unaffected 4.19.271 – ≤ 4.19.*
  • unaffected 5.4.243 – ≤ 5.4.*
  • unaffected 5.10.180 – ≤ 5.10.*
  • unaffected 5.15.111 – ≤ 5.15.*
  • unaffected 6.1.28 – ≤ 6.1.*
  • unaffected 6.2.15 – ≤ 6.2.*
  • unaffected 6.3.2 – ≤ 6.3.*
  • unaffected 6.4 – ≤ *

References (8)

• https://git.kernel.org/stable/c/0ce15000dee0ecd6f235f925a327803e2ef489c6 (opens in a new tab)
• https://git.kernel.org/stable/c/a34f6dcb78c654ab905642c1b4e7e5fbb4f0babe (opens in a new tab)
• https://git.kernel.org/stable/c/770b0613637f59f3091dda1ff0c23671a5326b9c (opens in a new tab)
• https://git.kernel.org/stable/c/40566def189c513be2c694681256d7486cc6e368 (opens in a new tab)
• https://git.kernel.org/stable/c/96d440bee177669dc0acedca0abd73bae6a9be8b (opens in a new tab)
• https://git.kernel.org/stable/c/11c87c8df2cae1d6be83c07e59fef0792de73482 (opens in a new tab)
• https://git.kernel.org/stable/c/14da044725a3ab10affa3566d29c15737c0e67a4 (opens in a new tab)
• https://git.kernel.org/stable/c/835659598c67907b98cd2aa57bb951dfaf675c69 (opens in a new tab)

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2023-53692](https://trackcve.app/badge/CVE-2023-53692.svg)](https://trackcve.app/cve/CVE-2023-53692)

Record last updated 5 Aug 2026, 09:15 UTC.