GHSA-P23J-C29J-HJGV
Vulnerability from github – Published: 2024-07-12 15:31 – Updated: 2025-09-25 21:30In the Linux kernel, the following vulnerability has been resolved:
ext4: fix uninitialized ratelimit_state->lock access in __ext4_fill_super()
In the following concurrency we will access the uninitialized rs->lock:
ext4_fill_super ext4_register_sysfs // sysfs registered msg_ratelimit_interval_ms // Other processes modify rs->interval to // non-zero via msg_ratelimit_interval_ms ext4_orphan_cleanup ext4_msg(sb, KERN_INFO, "Errors on filesystem, " __ext4_msg ratelimit(&(EXT4SB(sb)->s_msg_ratelimit_state) if (!rs->interval) // do nothing if interval is 0 return 1; raw_spin_trylock_irqsave(&rs->lock, flags) raw_spin_trylock(lock) _raw_spin_trylock raw_spin_trylock spin_acquire(&lock->dep_map, 0, 1, RET_IP) lock_acquire __lock_acquire register_lock_class assign_lock_key dump_stack(); ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10); raw_spin_lock_init(&rs->lock); // init rs->lock here
and get the following dump_stack:
========================================================= INFO: trying to register non-static key. The code is fine but needs lockdep annotation, or maybe you didn't initialize this object before use? turning off the locking correctness validator. CPU: 12 PID: 753 Comm: mount Tainted: G E 6.7.0-rc6-next-20231222 #504 [...] Call Trace: dump_stack_lvl+0xc5/0x170 dump_stack+0x18/0x30 register_lock_class+0x740/0x7c0 __lock_acquire+0x69/0x13a0 lock_acquire+0x120/0x450 _raw_spin_trylock+0x98/0xd0 ratelimit+0xf6/0x220 _ext4_msg+0x7f/0x160 [ext4] ext4_orphan_cleanup+0x665/0x740 [ext4] ext4_fill_super+0x21ea/0x2b10 [ext4] ext4_fill_super+0x14d/0x360 [ext4] [...] =========================================================
Normally interval is 0 until s_msg_ratelimit_state is initialized, so ___ratelimit() does nothing. But registering sysfs precedes initializing rs->lock, so it is possible to change rs->interval to a non-zero value via the msg_ratelimit_interval_ms interface of sysfs while rs->lock is uninitialized, and then a call to ext4_msg triggers the problem by accessing an uninitialized rs->lock. Therefore register sysfs after all initializations are complete to avoid such problems.
{
"affected": [],
"aliases": [
"CVE-2024-40998"
],
"database_specific": {
"cwe_ids": [
"CWE-908"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-07-12T13:15:20Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix uninitialized ratelimit_state-\u003elock access in __ext4_fill_super()\n\nIn the following concurrency we will access the uninitialized rs-\u003elock:\n\next4_fill_super\n ext4_register_sysfs\n // sysfs registered msg_ratelimit_interval_ms\n // Other processes modify rs-\u003einterval to\n // non-zero via msg_ratelimit_interval_ms\n ext4_orphan_cleanup\n ext4_msg(sb, KERN_INFO, \"Errors on filesystem, \"\n __ext4_msg\n ___ratelimit(\u0026(EXT4_SB(sb)-\u003es_msg_ratelimit_state)\n if (!rs-\u003einterval) // do nothing if interval is 0\n return 1;\n raw_spin_trylock_irqsave(\u0026rs-\u003elock, flags)\n raw_spin_trylock(lock)\n _raw_spin_trylock\n __raw_spin_trylock\n spin_acquire(\u0026lock-\u003edep_map, 0, 1, _RET_IP_)\n lock_acquire\n __lock_acquire\n register_lock_class\n assign_lock_key\n dump_stack();\n ratelimit_state_init(\u0026sbi-\u003es_msg_ratelimit_state, 5 * HZ, 10);\n raw_spin_lock_init(\u0026rs-\u003elock);\n // init rs-\u003elock here\n\nand get the following dump_stack:\n\n=========================================================\nINFO: trying to register non-static key.\nThe code is fine but needs lockdep annotation, or maybe\nyou didn\u0027t initialize this object before use?\nturning off the locking correctness validator.\nCPU: 12 PID: 753 Comm: mount Tainted: G E 6.7.0-rc6-next-20231222 #504\n[...]\nCall Trace:\n dump_stack_lvl+0xc5/0x170\n dump_stack+0x18/0x30\n register_lock_class+0x740/0x7c0\n __lock_acquire+0x69/0x13a0\n lock_acquire+0x120/0x450\n _raw_spin_trylock+0x98/0xd0\n ___ratelimit+0xf6/0x220\n __ext4_msg+0x7f/0x160 [ext4]\n ext4_orphan_cleanup+0x665/0x740 [ext4]\n __ext4_fill_super+0x21ea/0x2b10 [ext4]\n ext4_fill_super+0x14d/0x360 [ext4]\n[...]\n=========================================================\n\nNormally interval is 0 until s_msg_ratelimit_state is initialized, so\n___ratelimit() does nothing. But registering sysfs precedes initializing\nrs-\u003elock, so it is possible to change rs-\u003einterval to a non-zero value\nvia the msg_ratelimit_interval_ms interface of sysfs while rs-\u003elock is\nuninitialized, and then a call to ext4_msg triggers the problem by\naccessing an uninitialized rs-\u003elock. Therefore register sysfs after all\ninitializations are complete to avoid such problems.",
"id": "GHSA-p23j-c29j-hjgv",
"modified": "2025-09-25T21:30:18Z",
"published": "2024-07-12T15:31:29Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-40998"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/23afcd52af06880c6c913a0ad99022b8937b575c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/645267906944a9aeec9d5c56ee24a9096a288798"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b4b4fda34e535756f9e774fb2d09c4537b7dfd1c"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
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