CVE-2024-35979
raid1: fix use-after-free for original bio in raid1_write_request()
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
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 \n -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.
En el kernel de Linux, se resolvió la siguiente vulnerabilidad: raid1: corrige el uso después de liberar la biografía original en raid1_write_request() r1_bio->bios[] se usa para registrar nuevas biografías que se emitirán a los discos subyacentes; sin embargo, en raid1_write_request(), r1_bio->bios[] se configurará temporalmente en la biografía original. Mientras tanto, si se establece rdev bloqueado, se llamará a free_r1bio() causando que todos los r1_bio->bios[] sean liberados: raid1_write_request() r1_bio = alloc_r1bio(mddev, bio); -> r1_bio->bios[] es NULL para (i = 0; i < discos; i++) -> para cada rdev en conf // el primer rdev es normal r1_bio->bios[0] = bio; -> establecer en biografía original // el segundo rdev está bloqueado si (test_bit(Blocked, &rdev->flags)) break if (blocked_rdev) free_r1bio() put_all_bios() bio_put(r1_bio->bios[0]) -> biografía original es Scripts de prueba liberados: mdadm -CR /dev/md0 -l1 -n4 /dev/sd[abcd] --assume-clean fio -filename=/dev/md0 -ioengine=libaio -rw=write -bs=4k -numjobs= 1 \ -io Depth=128 -name=test -direct=1 eco bloqueado > /sys/block/md0/md/rd2/state Resultado de la prueba: ERROR bio-264 (No contaminado): Objeto ya libre ------ -------------------------------------------------- --------------------- Asignado en 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 Liberado en mempool_free_slab +0x1f/0x30 edad=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 _write_iter+0x309/0x440 aio_write+0x139/0x2f0 Dado que las BIOS para los discos subyacentes son aún no asignado, solucione este problema usando mempool_free() directamente para liberar r1_bio.
CVSS Scores
SSVC
- Decision:Track
Timeline
- 2024-05-17 CVE Reserved
- 2024-05-20 CVE Published
- 2024-05-21 EPSS Updated
- 2024-08-02 CVE Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
CAPEC
References (4)
| URL | Tag | Source |
|---|---|---|
| https://git.kernel.org/stable/c/992db13a4aee766c8bfbf046ad15c2db5fa7cab8 | Vuln. Introduced |
| URL | Date | SRC |
|---|
| URL | Date | SRC |
|---|
Affected Vendors, Products, and Versions
| Vendor | Product | Version | Other | Status | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 6.6 < 6.6.28 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.6 < 6.6.28" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 6.6 < 6.8.7 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.6 < 6.8.7" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 6.6 < 6.9 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.6 < 6.9" | en |
Affected
| ||||||