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VulnerabilityPublished Updated

CVE-2025-37742: Linux kernel · jfs: Fix uninit-value access of imap allocated in the diMount() function

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1088.95~20.04.1 : update Linux kernel when convenient.

Data as of 28 Oct 2026, 11:14 UTC

CVSS 3.1 base score
5.5Medium
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in 5.15.0-1088.95~20.04.1, 5.15.0-1094.103~20.04.1, 5.15.0-1114.123~20.04.1 +59
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 1 May 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threatsAffected
  • 6.17.0-1003.3 – 6.17.0-1017.17
10 affected builds
Fixed in–
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threatsAffected
  • <6.8.0-100.100
Fixed in
  • 6.8.0-100.100
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threatsAffected
  • <6.8.0-1046.49
Fixed in
  • 6.8.0-1046.49
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threatsAffected
  • <6.8.0-1046.52
Fixed in
  • 6.8.0-1046.52
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threatsAffected
  • 6.11.0-1008.8~24.04.1 – 6.11.0-1018.18~24.04.1
7 affected builds
Fixed in–
Ubuntu 24.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=nobleOther threatsAffected
  • <6.8.0-1046.53
Fixed in
  • 6.8.0-1046.53

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

In the Linux kernel, the following vulnerability has been resolved: jfs: Fix uninit-value access of imap allocated in the diMount() function syzbot reports that hex_dump_to_buffer is using uninit-value: ===================================================== BUG: KMSAN: uninit-value in hex_dump_to_buffer+0x888/0x1100 lib/hexdump.c:171 hex_dump_to_buffer+0x888/0x1100 lib/hexdump.c:171 print_hex_dump+0x13d/0x3e0 lib/hexdump.c:276 diFree+0x5ba/0x4350 fs/jfs/jfs_imap.c:876 jfs_evict_inode+0x510/0x550 fs/jfs/inode.c:156 evict+0x723/0xd10 fs/inode.c:796 iput_final fs/inode.c:1946 [inline] iput+0x97b/0xdb0 fs/inode.c:1972 txUpdateMap+0xf3e/0x1150 fs/jfs/jfs_txnmgr.c:2367 txLazyCommit fs/jfs/jfs_txnmgr.c:2664 [inline] jfs_lazycommit+0x627/0x11d0 fs/jfs/jfs_txnmgr.c:2733 kthread+0x6b9/0xef0 kernel/kthread.c:464 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Uninit was created at: slab_post_alloc_hook mm/slub.c:4121 [inline] slab_alloc_node mm/slub.c:4164 [inline] __kmalloc_cache_noprof+0x8e3/0xdf0 mm/slub.c:4320 kmalloc_noprof include/linux/slab.h:901 [inline] diMount+0x61/0x7f0 fs/jfs/jfs_imap.c:105 jfs_mount+0xa8e/0x11d0 fs/jfs/jfs_mount.c:176 jfs_fill_super+0xa47/0x17c0 fs/jfs/super.c:523 get_tree_bdev_flags+0x6ec/0x910 fs/super.c:1636 get_tree_bdev+0x37/0x50 fs/super.c:1659 jfs_get_tree+0x34/0x40 fs/jfs/super.c:635 vfs_get_tree+0xb1/0x5a0 fs/super.c:1814 do_new_mount+0x71f/0x15e0 fs/namespace.c:3560 path_mount+0x742/0x1f10 fs/namespace.c:3887 do_mount fs/namespace.c:3900 [inline] __do_sys_mount fs/namespace.c:4111 [inline] __se_sys_mount+0x71f/0x800 fs/namespace.c:4088 __x64_sys_mount+0xe4/0x150 fs/namespace.c:4088 x64_sys_call+0x39bf/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f ===================================================== The reason is that imap is not properly initialized after memory allocation. It will cause the snprintf() function to write uninitialized data into linebuf within hex_dump_to_buffer(). Fix this by using kzalloc instead of kmalloc to clear its content at the beginning in diMount().

References

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