Summary
In the Linux kernel, the following vulnerability has been resolved: jfs: Fix uninit-value access...
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
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().
Impact
CVE-2025-37742 has a CVSS score of 5.5 (Medium). The vector is requires local access, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2025-37742? CVE-2025-37742 is a medium-severity security vulnerability. No fixed version is listed yet.
- How severe is CVE-2025-37742? CVE-2025-37742 has a CVSS score of 5.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Is there a fix for CVE-2025-37742? No fixed version is listed for CVE-2025-37742 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2025-37742 exploitable, and should I be worried? Whether CVE-2025-37742 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-37742 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.