Security Vulnerabilities
- CVEs Published In October 2024
In the Linux kernel, the following vulnerability has been resolved:
jfs: check if leafidx greater than num leaves per dmap tree
syzbot report a out of bounds in dbSplit, it because dmt_leafidx greater
than num leaves per dmap tree, add a checking for dmt_leafidx in dbFindLeaf.
Shaggy:
Modified sanity check to apply to control pages as well as leaf pages.
In the Linux kernel, the following vulnerability has been resolved:
jfs: Fix uaf in dbFreeBits
[syzbot reported]
==================================================================
BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:587 [inline]
BUG: KASAN: slab-use-after-free in __mutex_lock+0xfe/0xd70 kernel/locking/mutex.c:752
Read of size 8 at addr ffff8880229254b0 by task syz-executor357/5216
CPU: 0 UID: 0 PID: 5216 Comm: syz-executor357 Not tainted 6.11.0-rc3-syzkaller-00156-gd7a5aa4b3c00 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:93 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x169/0x550 mm/kasan/report.c:488
kasan_report+0x143/0x180 mm/kasan/report.c:601
__mutex_lock_common kernel/locking/mutex.c:587 [inline]
__mutex_lock+0xfe/0xd70 kernel/locking/mutex.c:752
dbFreeBits+0x7ea/0xd90 fs/jfs/jfs_dmap.c:2390
dbFreeDmap fs/jfs/jfs_dmap.c:2089 [inline]
dbFree+0x35b/0x680 fs/jfs/jfs_dmap.c:409
dbDiscardAG+0x8a9/0xa20 fs/jfs/jfs_dmap.c:1650
jfs_ioc_trim+0x433/0x670 fs/jfs/jfs_discard.c:100
jfs_ioctl+0x2d0/0x3e0 fs/jfs/ioctl.c:131
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
Freed by task 5218:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
__kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2252 [inline]
slab_free mm/slub.c:4473 [inline]
kfree+0x149/0x360 mm/slub.c:4594
dbUnmount+0x11d/0x190 fs/jfs/jfs_dmap.c:278
jfs_mount_rw+0x4ac/0x6a0 fs/jfs/jfs_mount.c:247
jfs_remount+0x3d1/0x6b0 fs/jfs/super.c:454
reconfigure_super+0x445/0x880 fs/super.c:1083
vfs_cmd_reconfigure fs/fsopen.c:263 [inline]
vfs_fsconfig_locked fs/fsopen.c:292 [inline]
__do_sys_fsconfig fs/fsopen.c:473 [inline]
__se_sys_fsconfig+0xb6e/0xf80 fs/fsopen.c:345
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
[Analysis]
There are two paths (dbUnmount and jfs_ioc_trim) that generate race
condition when accessing bmap, which leads to the occurrence of uaf.
Use the lock s_umount to synchronize them, in order to avoid uaf caused
by race condition.
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: add list empty check to avoid null pointer issue
Add list empty check to avoid null pointer issues in some corner cases.
- list_for_each_entry_safe()
In the Linux kernel, the following vulnerability has been resolved:
ext4: aovid use-after-free in ext4_ext_insert_extent()
As Ojaswin mentioned in Link, in ext4_ext_insert_extent(), if the path is
reallocated in ext4_ext_create_new_leaf(), we'll use the stale path and
cause UAF. Below is a sample trace with dummy values:
ext4_ext_insert_extent
path = *ppath = 2000
ext4_ext_create_new_leaf(ppath)
ext4_find_extent(ppath)
path = *ppath = 2000
if (depth > path[0].p_maxdepth)
kfree(path = 2000);
*ppath = path = NULL;
path = kcalloc() = 3000
*ppath = 3000;
return path;
/* here path is still 2000, UAF! */
eh = path[depth].p_hdr
==================================================================
BUG: KASAN: slab-use-after-free in ext4_ext_insert_extent+0x26d4/0x3330
Read of size 8 at addr ffff8881027bf7d0 by task kworker/u36:1/179
CPU: 3 UID: 0 PID: 179 Comm: kworker/u6:1 Not tainted 6.11.0-rc2-dirty #866
Call Trace:
<TASK>
ext4_ext_insert_extent+0x26d4/0x3330
ext4_ext_map_blocks+0xe22/0x2d40
ext4_map_blocks+0x71e/0x1700
ext4_do_writepages+0x1290/0x2800
[...]
Allocated by task 179:
ext4_find_extent+0x81c/0x1f70
ext4_ext_map_blocks+0x146/0x2d40
ext4_map_blocks+0x71e/0x1700
ext4_do_writepages+0x1290/0x2800
ext4_writepages+0x26d/0x4e0
do_writepages+0x175/0x700
[...]
Freed by task 179:
kfree+0xcb/0x240
ext4_find_extent+0x7c0/0x1f70
ext4_ext_insert_extent+0xa26/0x3330
ext4_ext_map_blocks+0xe22/0x2d40
ext4_map_blocks+0x71e/0x1700
ext4_do_writepages+0x1290/0x2800
ext4_writepages+0x26d/0x4e0
do_writepages+0x175/0x700
[...]
==================================================================
So use *ppath to update the path to avoid the above problem.
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix slab-use-after-free in ext4_split_extent_at()
We hit the following use-after-free:
==================================================================
BUG: KASAN: slab-use-after-free in ext4_split_extent_at+0xba8/0xcc0
Read of size 2 at addr ffff88810548ed08 by task kworker/u20:0/40
CPU: 0 PID: 40 Comm: kworker/u20:0 Not tainted 6.9.0-dirty #724
Call Trace:
<TASK>
kasan_report+0x93/0xc0
ext4_split_extent_at+0xba8/0xcc0
ext4_split_extent.isra.0+0x18f/0x500
ext4_split_convert_extents+0x275/0x750
ext4_ext_handle_unwritten_extents+0x73e/0x1580
ext4_ext_map_blocks+0xe20/0x2dc0
ext4_map_blocks+0x724/0x1700
ext4_do_writepages+0x12d6/0x2a70
[...]
Allocated by task 40:
__kmalloc_noprof+0x1ac/0x480
ext4_find_extent+0xf3b/0x1e70
ext4_ext_map_blocks+0x188/0x2dc0
ext4_map_blocks+0x724/0x1700
ext4_do_writepages+0x12d6/0x2a70
[...]
Freed by task 40:
kfree+0xf1/0x2b0
ext4_find_extent+0xa71/0x1e70
ext4_ext_insert_extent+0xa22/0x3260
ext4_split_extent_at+0x3ef/0xcc0
ext4_split_extent.isra.0+0x18f/0x500
ext4_split_convert_extents+0x275/0x750
ext4_ext_handle_unwritten_extents+0x73e/0x1580
ext4_ext_map_blocks+0xe20/0x2dc0
ext4_map_blocks+0x724/0x1700
ext4_do_writepages+0x12d6/0x2a70
[...]
==================================================================
The flow of issue triggering is as follows:
ext4_split_extent_at
path = *ppath
ext4_ext_insert_extent(ppath)
ext4_ext_create_new_leaf(ppath)
ext4_find_extent(orig_path)
path = *orig_path
read_extent_tree_block
// return -ENOMEM or -EIO
ext4_free_ext_path(path)
kfree(path)
*orig_path = NULL
a. If err is -ENOMEM:
ext4_ext_dirty(path + path->p_depth)
// path use-after-free !!!
b. If err is -EIO and we have EXT_DEBUG defined:
ext4_ext_show_leaf(path)
eh = path[depth].p_hdr
// path also use-after-free !!!
So when trying to zeroout or fix the extent length, call ext4_find_extent()
to update the path.
In addition we use *ppath directly as an ext4_ext_show_leaf() input to
avoid possible use-after-free when EXT_DEBUG is defined, and to avoid
unnecessary path updates.
In the Linux kernel, the following vulnerability has been resolved:
mm, slub: avoid zeroing kmalloc redzone
Since commit 946fa0dbf2d8 ("mm/slub: extend redzone check to extra
allocated kmalloc space than requested"), setting orig_size treats
the wasted space (object_size - orig_size) as a redzone. However with
init_on_free=1 we clear the full object->size, including the redzone.
Additionally we clear the object metadata, including the stored orig_size,
making it zero, which makes check_object() treat the whole object as a
redzone.
These issues lead to the following BUG report with "slub_debug=FUZ
init_on_free=1":
[ 0.000000] =============================================================================
[ 0.000000] BUG kmalloc-8 (Not tainted): kmalloc Redzone overwritten
[ 0.000000] -----------------------------------------------------------------------------
[ 0.000000]
[ 0.000000] 0xffff000010032858-0xffff00001003285f @offset=2136. First byte 0x0 instead of 0xcc
[ 0.000000] FIX kmalloc-8: Restoring kmalloc Redzone 0xffff000010032858-0xffff00001003285f=0xcc
[ 0.000000] Slab 0xfffffdffc0400c80 objects=36 used=23 fp=0xffff000010032a18 flags=0x3fffe0000000200(workingset|node=0|zone=0|lastcpupid=0x1ffff)
[ 0.000000] Object 0xffff000010032858 @offset=2136 fp=0xffff0000100328c8
[ 0.000000]
[ 0.000000] Redzone ffff000010032850: cc cc cc cc cc cc cc cc ........
[ 0.000000] Object ffff000010032858: cc cc cc cc cc cc cc cc ........
[ 0.000000] Redzone ffff000010032860: cc cc cc cc cc cc cc cc ........
[ 0.000000] Padding ffff0000100328b4: 00 00 00 00 00 00 00 00 00 00 00 00 ............
[ 0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.11.0-rc3-next-20240814-00004-g61844c55c3f4 #144
[ 0.000000] Hardware name: NXP i.MX95 19X19 board (DT)
[ 0.000000] Call trace:
[ 0.000000] dump_backtrace+0x90/0xe8
[ 0.000000] show_stack+0x18/0x24
[ 0.000000] dump_stack_lvl+0x74/0x8c
[ 0.000000] dump_stack+0x18/0x24
[ 0.000000] print_trailer+0x150/0x218
[ 0.000000] check_object+0xe4/0x454
[ 0.000000] free_to_partial_list+0x2f8/0x5ec
To address the issue, use orig_size to clear the used area. And restore
the value of orig_size after clear the remaining area.
When CONFIG_SLUB_DEBUG not defined, (get_orig_size()' directly returns
s->object_size. So when using memset to init the area, the size can simply
be orig_size, as orig_size returns object_size when CONFIG_SLUB_DEBUG not
enabled. And orig_size can never be bigger than object_size.
In the Linux kernel, the following vulnerability has been resolved:
platform/x86: ISST: Fix the KASAN report slab-out-of-bounds bug
Attaching SST PCI device to VM causes "BUG: KASAN: slab-out-of-bounds".
kasan report:
[ 19.411889] ==================================================================
[ 19.413702] BUG: KASAN: slab-out-of-bounds in _isst_if_get_pci_dev+0x3d5/0x400 [isst_if_common]
[ 19.415634] Read of size 8 at addr ffff888829e65200 by task cpuhp/16/113
[ 19.417368]
[ 19.418627] CPU: 16 PID: 113 Comm: cpuhp/16 Tainted: G E 6.9.0 #10
[ 19.420435] Hardware name: VMware, Inc. VMware20,1/440BX Desktop Reference Platform, BIOS VMW201.00V.20192059.B64.2207280713 07/28/2022
[ 19.422687] Call Trace:
[ 19.424091] <TASK>
[ 19.425448] dump_stack_lvl+0x5d/0x80
[ 19.426963] ? _isst_if_get_pci_dev+0x3d5/0x400 [isst_if_common]
[ 19.428694] print_report+0x19d/0x52e
[ 19.430206] ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[ 19.431837] ? _isst_if_get_pci_dev+0x3d5/0x400 [isst_if_common]
[ 19.433539] kasan_report+0xf0/0x170
[ 19.435019] ? _isst_if_get_pci_dev+0x3d5/0x400 [isst_if_common]
[ 19.436709] _isst_if_get_pci_dev+0x3d5/0x400 [isst_if_common]
[ 19.438379] ? __pfx_sched_clock_cpu+0x10/0x10
[ 19.439910] isst_if_cpu_online+0x406/0x58f [isst_if_common]
[ 19.441573] ? __pfx_isst_if_cpu_online+0x10/0x10 [isst_if_common]
[ 19.443263] ? ttwu_queue_wakelist+0x2c1/0x360
[ 19.444797] cpuhp_invoke_callback+0x221/0xec0
[ 19.446337] cpuhp_thread_fun+0x21b/0x610
[ 19.447814] ? __pfx_cpuhp_thread_fun+0x10/0x10
[ 19.449354] smpboot_thread_fn+0x2e7/0x6e0
[ 19.450859] ? __pfx_smpboot_thread_fn+0x10/0x10
[ 19.452405] kthread+0x29c/0x350
[ 19.453817] ? __pfx_kthread+0x10/0x10
[ 19.455253] ret_from_fork+0x31/0x70
[ 19.456685] ? __pfx_kthread+0x10/0x10
[ 19.458114] ret_from_fork_asm+0x1a/0x30
[ 19.459573] </TASK>
[ 19.460853]
[ 19.462055] Allocated by task 1198:
[ 19.463410] kasan_save_stack+0x30/0x50
[ 19.464788] kasan_save_track+0x14/0x30
[ 19.466139] __kasan_kmalloc+0xaa/0xb0
[ 19.467465] __kmalloc+0x1cd/0x470
[ 19.468748] isst_if_cdev_register+0x1da/0x350 [isst_if_common]
[ 19.470233] isst_if_mbox_init+0x108/0xff0 [isst_if_mbox_msr]
[ 19.471670] do_one_initcall+0xa4/0x380
[ 19.472903] do_init_module+0x238/0x760
[ 19.474105] load_module+0x5239/0x6f00
[ 19.475285] init_module_from_file+0xd1/0x130
[ 19.476506] idempotent_init_module+0x23b/0x650
[ 19.477725] __x64_sys_finit_module+0xbe/0x130
[ 19.476506] idempotent_init_module+0x23b/0x650
[ 19.477725] __x64_sys_finit_module+0xbe/0x130
[ 19.478920] do_syscall_64+0x82/0x160
[ 19.480036] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 19.481292]
[ 19.482205] The buggy address belongs to the object at ffff888829e65000
which belongs to the cache kmalloc-512 of size 512
[ 19.484818] The buggy address is located 0 bytes to the right of
allocated 512-byte region [ffff888829e65000, ffff888829e65200)
[ 19.487447]
[ 19.488328] The buggy address belongs to the physical page:
[ 19.489569] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888829e60c00 pfn:0x829e60
[ 19.491140] head: order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
[ 19.492466] anon flags: 0x57ffffc0000840(slab|head|node=1|zone=2|lastcpupid=0x1fffff)
[ 19.493914] page_type: 0xffffffff()
[ 19.494988] raw: 0057ffffc0000840 ffff88810004cc80 0000000000000000 0000000000000001
[ 19.496451] raw: ffff888829e60c00 0000000080200018 00000001ffffffff 0000000000000000
[ 19.497906] head: 0057ffffc0000840 ffff88810004cc80 0000000000000000 0000000000000001
[ 19.499379] head: ffff888829e60c00 0000000080200018 00000001ffffffff 0000000000000000
[ 19.500844] head: 0057ffffc0000003 ffffea0020a79801 ffffea0020a79848 00000000ffffffff
[ 19.502316] head: 0000000800000000 0000000000000000 00000000ffffffff 0000000000000000
[ 19.503784] page dumped because: k
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to don't panic system for no free segment fault injection
f2fs: fix to don't panic system for no free segment fault injection
syzbot reports a f2fs bug as below:
F2FS-fs (loop0): inject no free segment in get_new_segment of __allocate_new_segment+0x1ce/0x940 fs/f2fs/segment.c:3167
F2FS-fs (loop0): Stopped filesystem due to reason: 7
------------[ cut here ]------------
kernel BUG at fs/f2fs/segment.c:2748!
CPU: 0 UID: 0 PID: 5109 Comm: syz-executor304 Not tainted 6.11.0-rc6-syzkaller-00363-g89f5e14d05b4 #0
RIP: 0010:get_new_segment fs/f2fs/segment.c:2748 [inline]
RIP: 0010:new_curseg+0x1f61/0x1f70 fs/f2fs/segment.c:2836
Call Trace:
__allocate_new_segment+0x1ce/0x940 fs/f2fs/segment.c:3167
f2fs_allocate_new_section fs/f2fs/segment.c:3181 [inline]
f2fs_allocate_pinning_section+0xfa/0x4e0 fs/f2fs/segment.c:3195
f2fs_expand_inode_data+0x5d6/0xbb0 fs/f2fs/file.c:1799
f2fs_fallocate+0x448/0x960 fs/f2fs/file.c:1903
vfs_fallocate+0x553/0x6c0 fs/open.c:334
do_vfs_ioctl+0x2592/0x2e50 fs/ioctl.c:886
__do_sys_ioctl fs/ioctl.c:905 [inline]
__se_sys_ioctl+0x81/0x170 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0010:get_new_segment fs/f2fs/segment.c:2748 [inline]
RIP: 0010:new_curseg+0x1f61/0x1f70 fs/f2fs/segment.c:2836
The root cause is when we inject no free segment fault into f2fs,
we should not panic system, fix it.
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix a sdiv overflow issue
Zac Ecob reported a problem where a bpf program may cause kernel crash due
to the following error:
Oops: divide error: 0000 [#1] PREEMPT SMP KASAN PTI
The failure is due to the below signed divide:
LLONG_MIN/-1 where LLONG_MIN equals to -9,223,372,036,854,775,808.
LLONG_MIN/-1 is supposed to give a positive number 9,223,372,036,854,775,808,
but it is impossible since for 64-bit system, the maximum positive
number is 9,223,372,036,854,775,807. On x86_64, LLONG_MIN/-1 will
cause a kernel exception. On arm64, the result for LLONG_MIN/-1 is
LLONG_MIN.
Further investigation found all the following sdiv/smod cases may trigger
an exception when bpf program is running on x86_64 platform:
- LLONG_MIN/-1 for 64bit operation
- INT_MIN/-1 for 32bit operation
- LLONG_MIN%-1 for 64bit operation
- INT_MIN%-1 for 32bit operation
where -1 can be an immediate or in a register.
On arm64, there are no exceptions:
- LLONG_MIN/-1 = LLONG_MIN
- INT_MIN/-1 = INT_MIN
- LLONG_MIN%-1 = 0
- INT_MIN%-1 = 0
where -1 can be an immediate or in a register.
Insn patching is needed to handle the above cases and the patched codes
produced results aligned with above arm64 result. The below are pseudo
codes to handle sdiv/smod exceptions including both divisor -1 and divisor 0
and the divisor is stored in a register.
sdiv:
tmp = rX
tmp += 1 /* [-1, 0] -> [0, 1]
if tmp >(unsigned) 1 goto L2
if tmp == 0 goto L1
rY = 0
L1:
rY = -rY;
goto L3
L2:
rY /= rX
L3:
smod:
tmp = rX
tmp += 1 /* [-1, 0] -> [0, 1]
if tmp >(unsigned) 1 goto L1
if tmp == 1 (is64 ? goto L2 : goto L3)
rY = 0;
goto L2
L1:
rY %= rX
L2:
goto L4 // only when !is64
L3:
wY = wY // only when !is64
L4:
[1] https://lore.kernel.org/bpf/tPJLTEh7S_DxFEqAI2Ji5MBSoZVg7_G-Py2iaZpAaWtM961fFTWtsnlzwvTbzBzaUzwQAoNATXKUlt0LZOFgnDcIyKCswAnAGdUF3LBrhGQ=@protonmail.com/
In the Linux kernel, the following vulnerability has been resolved:
ext4: avoid use-after-free in ext4_ext_show_leaf()
In ext4_find_extent(), path may be freed by error or be reallocated, so
using a previously saved *ppath may have been freed and thus may trigger
use-after-free, as follows:
ext4_split_extent
path = *ppath;
ext4_split_extent_at(ppath)
path = ext4_find_extent(ppath)
ext4_split_extent_at(ppath)
// ext4_find_extent fails to free path
// but zeroout succeeds
ext4_ext_show_leaf(inode, path)
eh = path[depth].p_hdr
// path use-after-free !!!
Similar to ext4_split_extent_at(), we use *ppath directly as an input to
ext4_ext_show_leaf(). Fix a spelling error by the way.
Same problem in ext4_ext_handle_unwritten_extents(). Since 'path' is only
used in ext4_ext_show_leaf(), remove 'path' and use *ppath directly.
This issue is triggered only when EXT_DEBUG is defined and therefore does
not affect functionality.