ghsa-q2cp-mh84-p47v
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
raid1: fix use-after-free for original bio in raid1_write_request()
r1_bio->bios[] is used to record new bios that will be issued to underlying disks, however, in raid1_write_request(), r1_bio->bios[] will set to the original bio temporarily. Meanwhile, if blocked rdev is set, free_r1bio() will be called causing that all r1_bio->bios[] to be freed:
raid1_write_request() r1_bio = alloc_r1bio(mddev, bio); -> r1_bio->bios[] is NULL for (i = 0; i < disks; i++) -> for each rdev in conf // first rdev is normal r1_bio->bios[0] = bio; -> set to original bio // second rdev is blocked if (test_bit(Blocked, &rdev->flags)) break
if (blocked_rdev) free_r1bio() put_all_bios() bio_put(r1_bio->bios[0]) -> original bio is freed
Test scripts:
mdadm -CR /dev/md0 -l1 -n4 /dev/sd[abcd] --assume-clean fio -filename=/dev/md0 -ioengine=libaio -rw=write -bs=4k -numjobs=1 \ -iodepth=128 -name=test -direct=1 echo blocked > /sys/block/md0/md/rd2/state
Test result:
BUG bio-264 (Not tainted): Object already free
Allocated in mempool_alloc_slab+0x24/0x50 age=1 cpu=1 pid=869 kmem_cache_alloc+0x324/0x480 mempool_alloc_slab+0x24/0x50 mempool_alloc+0x6e/0x220 bio_alloc_bioset+0x1af/0x4d0 blkdev_direct_IO+0x164/0x8a0 blkdev_write_iter+0x309/0x440 aio_write+0x139/0x2f0 io_submit_one+0x5ca/0xb70 __do_sys_io_submit+0x86/0x270 __x64_sys_io_submit+0x22/0x30 do_syscall_64+0xb1/0x210 entry_SYSCALL_64_after_hwframe+0x6c/0x74 Freed in mempool_free_slab+0x1f/0x30 age=1 cpu=1 pid=869 kmem_cache_free+0x28c/0x550 mempool_free_slab+0x1f/0x30 mempool_free+0x40/0x100 bio_free+0x59/0x80 bio_put+0xf0/0x220 free_r1bio+0x74/0xb0 raid1_make_request+0xadf/0x1150 md_handle_request+0xc7/0x3b0 md_submit_bio+0x76/0x130 __submit_bio+0xd8/0x1d0 submit_bio_noacct_nocheck+0x1eb/0x5c0 submit_bio_noacct+0x169/0xd40 submit_bio+0xee/0x1d0 blkdev_direct_IO+0x322/0x8a0 blkdev_write_iter+0x309/0x440 aio_write+0x139/0x2f0
Since that bios for underlying disks are not allocated yet, fix this problem by using mempool_free() directly to free the r1_bio.
{
"affected": [],
"aliases": [
"CVE-2024-35979"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-05-20T10:15:12Z",
"severity": null
},
"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, \u0026rdev-\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.",
"id": "GHSA-q2cp-mh84-p47v",
"modified": "2024-05-20T12:30:29Z",
"published": "2024-05-20T12:30:29Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-35979"
},
{
"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"
}
],
"schema_version": "1.4.0",
"severity": []
}