{"cve":"CVE-2024-49903","nvd":{"published":"2024-10-21T18:15:12.873","modified":"2026-10-15T01:19:00.923","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\njfs: Fix uaf in dbFreeBits\n\n[syzbot reported]\n==================================================================\nBUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:587 [inline]\nBUG: KASAN: slab-use-after-free in __mutex_lock+0xfe/0xd70 kernel/locking/mutex.c:752\nRead of size 8 at addr ffff8880229254b0 by task syz-executor357/5216\n\nCPU: 0 UID: 0 PID: 5216 Comm: syz-executor357 Not tainted 6.11.0-rc3-syzkaller-00156-gd7a5aa4b3c00 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024\nCall Trace:\n <TASK>\n __dump_stack lib/dump_stack.c:93 [inline]\n dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119\n print_address_description mm/kasan/report.c:377 [inline]\n print_report+0x169/0x550 mm/kasan/report.c:488\n kasan_report+0x143/0x180 mm/kasan/report.c:601\n __mutex_lock_common kernel/locking/mutex.c:587 [inline]\n __mutex_lock+0xfe/0xd70 kernel/locking/mutex.c:752\n dbFreeBits+0x7ea/0xd90 fs/jfs/jfs_dmap.c:2390\n dbFreeDmap fs/jfs/jfs_dmap.c:2089 [inline]\n dbFree+0x35b/0x680 fs/jfs/jfs_dmap.c:409\n dbDiscardAG+0x8a9/0xa20 fs/jfs/jfs_dmap.c:1650\n jfs_ioc_trim+0x433/0x670 fs/jfs/jfs_discard.c:100\n jfs_ioctl+0x2d0/0x3e0 fs/jfs/ioctl.c:131\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:907 [inline]\n __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n\nFreed by task 5218:\n kasan_save_stack mm/kasan/common.c:47 [inline]\n kasan_save_track+0x3f/0x80 mm/kasan/common.c:68\n kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579\n poison_slab_object+0xe0/0x150 mm/kasan/common.c:240\n __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256\n kasan_slab_free include/linux/kasan.h:184 [inline]\n slab_free_hook mm/slub.c:2252 [inline]\n slab_free mm/slub.c:4473 [inline]\n kfree+0x149/0x360 mm/slub.c:4594\n dbUnmount+0x11d/0x190 fs/jfs/jfs_dmap.c:278\n jfs_mount_rw+0x4ac/0x6a0 fs/jfs/jfs_mount.c:247\n jfs_remount+0x3d1/0x6b0 fs/jfs/super.c:454\n reconfigure_super+0x445/0x880 fs/super.c:1083\n vfs_cmd_reconfigure fs/fsopen.c:263 [inline]\n vfs_fsconfig_locked fs/fsopen.c:292 [inline]\n __do_sys_fsconfig fs/fsopen.c:473 [inline]\n __se_sys_fsconfig+0xb6e/0xf80 fs/fsopen.c:345\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n[Analysis]\nThere are two paths (dbUnmount and jfs_ioc_trim) that generate race\ncondition when accessing bmap, which leads to the occurrence of uaf.\n\nUse the lock s_umount to synchronize them, in order to avoid uaf caused\nby race condition.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.0},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/0c238da83f56bb895cab1e5851d034ac45b158d1","https://git.kernel.org/stable/c/3126ccde51f51b0648c8cdccaf916e8bd062e972","https://git.kernel.org/stable/c/4218b31ecc7af7e191768d32e32ed4386d8f9b76","https://git.kernel.org/stable/c/4ac58f7734937f3249da734ede946dfb3b1af5e4","https://git.kernel.org/stable/c/95accb7183badca387f7a8d19a2475cf3089f148"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:56:33.105311382+00:00"},"epss":{"cve":"CVE-2024-49903","score":0.00255,"percentile":0.16888,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}