Skip to content
CVE PROGRAM SOURCE RECORD5.5 Medium

CVE-2024-39276

ext4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find()

Read JSON ↗CVE.org ↗
Status
Published
Published
Updated
Assigning organization
Linux

Description

In the Linux kernel, the following vulnerability has been resolved: ext4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find() Syzbot reports a warning as follows: ============================================ WARNING: CPU: 0 PID: 5075 at fs/mbcache.c:419 mb_cache_destroy+0x224/0x290 Modules linked in: CPU: 0 PID: 5075 Comm: syz-executor199 Not tainted 6.9.0-rc6-gb947cc5bf6d7 RIP: 0010:mb_cache_destroy+0x224/0x290 fs/mbcache.c:419 Call Trace: <TASK> ext4_put_super+0x6d4/0xcd0 fs/ext4/super.c:1375 generic_shutdown_super+0x136/0x2d0 fs/super.c:641 kill_block_super+0x44/0x90 fs/super.c:1675 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7327 [...] ============================================ This is because when finding an entry in ext4_xattr_block_cache_find(), if ext4_sb_bread() returns -ENOMEM, the ce's e_refcnt, which has already grown in the __entry_find(), won't be put away, and eventually trigger the above issue in mb_cache_destroy() due to reference count leakage. So call mb_cache_entry_put() on the -ENOMEM error branch as a quick fix.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • b878c8a7f08f0c225b6a46ba1ac867e9c5d17807 to < 9ad75e78747b5a50dc5a52f0f8e92e920a653f16affected
  • fb265c9cb49e2074ddcdd4de99728aefdd3b3592 to < 896a7e7d0d555ad8b2b46af0c2fa7de7467f9483affected
  • fb265c9cb49e2074ddcdd4de99728aefdd3b3592 to < 76dc776153a47372719d664e0fc50d6355791abbaffected
  • fb265c9cb49e2074ddcdd4de99728aefdd3b3592 to < 681ff9a09accd8a4379f8bd30b7a1641ee19bb3eaffected
  • fb265c9cb49e2074ddcdd4de99728aefdd3b3592 to < e941b712e758f615d311946bf98216e79145ccd9affected
  • fb265c9cb49e2074ddcdd4de99728aefdd3b3592 to < a95df6f04f2c37291adf26a74205cde0314d4577affected
  • fb265c9cb49e2074ddcdd4de99728aefdd3b3592 to < b37c0edef4e66fb21a2fbc211471195a383e5ab8affected
  • fb265c9cb49e2074ddcdd4de99728aefdd3b3592 to < 0c0b4a49d3e7f49690a6827a41faeffad5df7e21affected
  • 9da1f6d06b7a6d068e68fcfd7cbbf6b586d888e1affected
  • 81313ed2c705d958744882a269bf4a5e3ddec95eaffected
  • 4.19.14 to < 4.19.316affected
  • 4.14.92 to < 4.15affected
  • 4.20.1 to < 4.21affected

Linux Linux

Default version status: affected

  • 5.0affected
  • 0 to < 5.0unaffected
  • 4.19.316 to ≤ 4.19.*unaffected
  • 5.4.278 to ≤ 5.4.*unaffected
  • 5.10.219 to ≤ 5.10.*unaffected
  • 5.15.161 to ≤ 5.15.*unaffected
  • 6.1.94 to ≤ 6.1.*unaffected
  • 6.6.34 to ≤ 6.6.*unaffected
  • 6.9.5 to ≤ 6.9.*unaffected
  • 6.10 to ≤ *unaffected

References