In the Linux kernel, the following vulnerability has been resolved:
fbmem: Do not delete the mode that is still in use
The execution of fb_delete_videomode() is not based on the result of the
previous fbcon_mode_deleted(). As a result, the mode is directly deleted,
regardless of whether it is still in use, which may cause UAF.
==================================================================
BUG: KASAN: use-after-free in fb_mode_is_equal+0x36e/0x5e0
drivers/video/fbdev/core/modedb.c:924
Read of size 4 at addr ffff88807e0ddb1c by task syz-executor.0/18962
CPU: 2 PID: 18962 Comm: syz-executor.0 Not tainted 5.10.45-rc1+ #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS …
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x137/0x1be lib/dump_stack.c:118
print_address_description+0x6c/0x640 mm/kasan/report.c:385
__kasan_report mm/kasan/report.c:545 [inline]
kasan_report+0x13d/0x1e0 mm/kasan/report.c:562
fb_mode_is_equal+0x36e/0x5e0 drivers/video/fbdev/core/modedb.c:924
fbcon_mode_deleted+0x16a/0x220 drivers/video/fbdev/core/fbcon.c:2746
fb_set_var+0x1e1/0xdb0 drivers/video/fbdev/core/fbmem.c:975
do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Freed by task 18960:
kasan_save_stack mm/kasan/common.c:48 [inline]
kasan_set_track+0x3d/0x70 mm/kasan/common.c:56
kasan_set_free_info+0x17/0x30 mm/kasan/generic.c:355
__kasan_slab_free+0x108/0x140 mm/kasan/common.c:422
slab_free_hook mm/slub.c:1541 [inline]
slab_free_freelist_hook+0xd6/0x1a0 mm/slub.c:1574
slab_free mm/slub.c:3139 [inline]
kfree+0xca/0x3d0 mm/slub.c:4121
fb_delete_videomode+0x56a/0x820 drivers/video/fbdev/core/modedb.c:1104
fb_set_var+0x1f3/0xdb0 drivers/video/fbdev/core/fbmem.c:978
do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Vendor | Product | Version | CPE |
---|---|---|---|
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
[
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/video/fbdev/core/fbmem.c"
],
"versions": [
{
"version": "13ff178ccd6d",
"lessThan": "359311b85ebe",
"status": "affected",
"versionType": "git"
},
{
"version": "13ff178ccd6d",
"lessThan": "087bff9acd2e",
"status": "affected",
"versionType": "git"
},
{
"version": "13ff178ccd6d",
"lessThan": "f193509afc7f",
"status": "affected",
"versionType": "git"
},
{
"version": "13ff178ccd6d",
"lessThan": "d6e76469157d",
"status": "affected",
"versionType": "git"
},
{
"version": "13ff178ccd6d",
"lessThan": "0af778269a52",
"status": "affected",
"versionType": "git"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/video/fbdev/core/fbmem.c"
],
"versions": [
{
"version": "5.3",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.3",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.4.134",
"lessThanOrEqual": "5.4.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.10.52",
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.12.19",
"lessThanOrEqual": "5.12.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.13.4",
"lessThanOrEqual": "5.13.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.14",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
]
}
]
git.kernel.org/stable/c/087bff9acd2ec6db3f61aceb3224bde90fe0f7f8
git.kernel.org/stable/c/0af778269a522c988ef0b4188556aba97fb420cc
git.kernel.org/stable/c/359311b85ebec7c07c3a08ae2f3def946cad33fa
git.kernel.org/stable/c/d6e76469157d8f240e5dec6f8411aa8d306b1126
git.kernel.org/stable/c/f193509afc7ff37a46862610c93b896044d5b693