{"id":"CVE-2024-35979","summary":"raid1: fix use-after-free for original bio in raid1_write_request()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nraid1: fix use-after-free for original bio in raid1_write_request()\n\nr1_bio-\u003ebios[] is used to record new bios that will be issued to\nunderlying disks, however, in raid1_write_request(), r1_bio-\u003ebios[]\nwill set to the original bio temporarily. Meanwhile, if blocked rdev\nis set, free_r1bio() will be called causing that all r1_bio-\u003ebios[]\nto be freed:\n\nraid1_write_request()\n r1_bio = alloc_r1bio(mddev, bio); -\u003e r1_bio-\u003ebios[] is NULL\n for (i = 0;  i \u003c disks; i++) -\u003e for each rdev in conf\n  // first rdev is normal\n  r1_bio-\u003ebios[0] = bio; -\u003e set to original bio\n  // second rdev is blocked\n  if (test_bit(Blocked, &rdev-\u003eflags))\n   break\n\n if (blocked_rdev)\n  free_r1bio()\n   put_all_bios()\n    bio_put(r1_bio-\u003ebios[0]) -\u003e original bio is freed\n\nTest scripts:\n\nmdadm -CR /dev/md0 -l1 -n4 /dev/sd[abcd] --assume-clean\nfio -filename=/dev/md0 -ioengine=libaio -rw=write -bs=4k -numjobs=1 \\\n    -iodepth=128 -name=test -direct=1\necho blocked \u003e /sys/block/md0/md/rd2/state\n\nTest result:\n\nBUG bio-264 (Not tainted): Object already free\n-----------------------------------------------------------------------------\n\nAllocated in mempool_alloc_slab+0x24/0x50 age=1 cpu=1 pid=869\n kmem_cache_alloc+0x324/0x480\n mempool_alloc_slab+0x24/0x50\n mempool_alloc+0x6e/0x220\n bio_alloc_bioset+0x1af/0x4d0\n blkdev_direct_IO+0x164/0x8a0\n blkdev_write_iter+0x309/0x440\n aio_write+0x139/0x2f0\n io_submit_one+0x5ca/0xb70\n __do_sys_io_submit+0x86/0x270\n __x64_sys_io_submit+0x22/0x30\n do_syscall_64+0xb1/0x210\n entry_SYSCALL_64_after_hwframe+0x6c/0x74\nFreed in mempool_free_slab+0x1f/0x30 age=1 cpu=1 pid=869\n kmem_cache_free+0x28c/0x550\n mempool_free_slab+0x1f/0x30\n mempool_free+0x40/0x100\n bio_free+0x59/0x80\n bio_put+0xf0/0x220\n free_r1bio+0x74/0xb0\n raid1_make_request+0xadf/0x1150\n md_handle_request+0xc7/0x3b0\n md_submit_bio+0x76/0x130\n __submit_bio+0xd8/0x1d0\n submit_bio_noacct_nocheck+0x1eb/0x5c0\n submit_bio_noacct+0x169/0xd40\n submit_bio+0xee/0x1d0\n blkdev_direct_IO+0x322/0x8a0\n blkdev_write_iter+0x309/0x440\n aio_write+0x139/0x2f0\n\nSince that bios for underlying disks are not allocated yet, fix this\nproblem by using mempool_free() directly to free the r1_bio.","modified":"2026-04-02T11:59:53.867800Z","published":"2024-05-20T09:42:04.424Z","related":["SUSE-SU-2024:2360-1","SUSE-SU-2024:2381-1","SUSE-SU-2024:2561-1","SUSE-SU-2024:2571-1","SUSE-SU-2024:2894-1","SUSE-SU-2024:2896-1","SUSE-SU-2024:2939-1","SUSE-SU-2024:2947-1","SUSE-SU-2024:2973-1","SUSE-SU-2025:20008-1","SUSE-SU-2025:20028-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/35xxx/CVE-2024-35979.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/3f28d49a328fe20926995d5fbdc92da665596268"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f423f41b7679c09abb26d2bd54be5cbef23c9446"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fcf3f7e2fc8a53a6140beee46ec782a4c88e4744"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/35xxx/CVE-2024-35979.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-35979"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"992db13a4aee766c8bfbf046ad15c2db5fa7cab8"},{"fixed":"3f28d49a328fe20926995d5fbdc92da665596268"},{"fixed":"f423f41b7679c09abb26d2bd54be5cbef23c9446"},{"fixed":"fcf3f7e2fc8a53a6140beee46ec782a4c88e4744"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-35979.json"}}],"schema_version":"1.7.5"}