Security Vulnerabilities - CVEs Published In October 2024
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix potential null-ptr-deref in nilfs_btree_insert()
Patch series "nilfs2: fix potential issues with empty b-tree nodes".
This series addresses three potential issues with empty b-tree nodes that
can occur with corrupted filesystem images, including one recently
discovered by syzbot.
This patch (of 3):
If a b-tree is broken on the device, and the b-tree height is greater than
2 (the level of the root node is greater than 1) even if the number of
child nodes of the b-tree root is 0, a NULL pointer dereference occurs in
nilfs_btree_prepare_insert(), which is called from nilfs_btree_insert().
This is because, when the number of child nodes of the b-tree root is 0,
nilfs_btree_do_lookup() does not set the block buffer head in any of
path[x].bp_bh, leaving it as the initial value of NULL, but if the level
of the b-tree root node is greater than 1, nilfs_btree_get_nonroot_node(),
which accesses the buffer memory of path[x].bp_bh, is called.
Fix this issue by adding a check to nilfs_btree_root_broken(), which
performs sanity checks when reading the root node from the device, to
detect this inconsistency.
Thanks to Lizhi Xu for trying to solve the bug and clarifying the cause
early on.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
ext4: check stripe size compatibility on remount as well
We disable stripe size in __ext4_fill_super if it is not a multiple of
the cluster ratio however this check is missed when trying to remount.
This can leave us with cases where stripe < cluster_ratio after
remount:set making EXT4_B2C(sbi->s_stripe) become 0 that can cause some
unforeseen bugs like divide by 0.
Fix that by adding the check in remount path as well.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
ext4: avoid OOB when system.data xattr changes underneath the filesystem
When looking up for an entry in an inlined directory, if e_value_offs is
changed underneath the filesystem by some change in the block device, it
will lead to an out-of-bounds access that KASAN detects as an UAF.
EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.
loop0: detected capacity change from 2048 to 2047
==================================================================
BUG: KASAN: use-after-free in ext4_search_dir+0xf2/0x1c0 fs/ext4/namei.c:1500
Read of size 1 at addr ffff88803e91130f by task syz-executor269/5103
CPU: 0 UID: 0 PID: 5103 Comm: syz-executor269 Not tainted 6.11.0-rc4-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
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
ext4_search_dir+0xf2/0x1c0 fs/ext4/namei.c:1500
ext4_find_inline_entry+0x4be/0x5e0 fs/ext4/inline.c:1697
__ext4_find_entry+0x2b4/0x1b30 fs/ext4/namei.c:1573
ext4_lookup_entry fs/ext4/namei.c:1727 [inline]
ext4_lookup+0x15f/0x750 fs/ext4/namei.c:1795
lookup_one_qstr_excl+0x11f/0x260 fs/namei.c:1633
filename_create+0x297/0x540 fs/namei.c:3980
do_symlinkat+0xf9/0x3a0 fs/namei.c:4587
__do_sys_symlinkat fs/namei.c:4610 [inline]
__se_sys_symlinkat fs/namei.c:4607 [inline]
__x64_sys_symlinkat+0x95/0xb0 fs/namei.c:4607
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: 0033:0x7f3e73ced469
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff4d40c258 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 0032656c69662f2e RCX: 00007f3e73ced469
RDX: 0000000020000200 RSI: 00000000ffffff9c RDI: 00000000200001c0
RBP: 0000000000000000 R08: 00007fff4d40c290 R09: 00007fff4d40c290
R10: 0023706f6f6c2f76 R11: 0000000000000246 R12: 00007fff4d40c27c
R13: 0000000000000003 R14: 431bde82d7b634db R15: 00007fff4d40c2b0
</TASK>
Calling ext4_xattr_ibody_find right after reading the inode with
ext4_get_inode_loc will lead to a check of the validity of the xattrs,
avoiding this problem.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fail verification for sign-extension of packet data/data_end/data_meta
syzbot reported a kernel crash due to
commit 1f1e864b6555 ("bpf: Handle sign-extenstin ctx member accesses").
The reason is due to sign-extension of 32-bit load for
packet data/data_end/data_meta uapi field.
The original code looks like:
r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */
r3 = *(u32 *)(r1 + 80) /* load __sk_buff->data_end */
r0 = r2
r0 += 8
if r3 > r0 goto +1
...
Note that __sk_buff->data load has 32-bit sign extension.
After verification and convert_ctx_accesses(), the final asm code looks like:
r2 = *(u64 *)(r1 +208)
r2 = (s32)r2
r3 = *(u64 *)(r1 +80)
r0 = r2
r0 += 8
if r3 > r0 goto pc+1
...
Note that 'r2 = (s32)r2' may make the kernel __sk_buff->data address invalid
which may cause runtime failure.
Currently, in C code, typically we have
void *data = (void *)(long)skb->data;
void *data_end = (void *)(long)skb->data_end;
...
and it will generate
r2 = *(u64 *)(r1 +208)
r3 = *(u64 *)(r1 +80)
r0 = r2
r0 += 8
if r3 > r0 goto pc+1
If we allow sign-extension,
void *data = (void *)(long)(int)skb->data;
void *data_end = (void *)(long)skb->data_end;
...
the generated code looks like
r2 = *(u64 *)(r1 +208)
r2 <<= 32
r2 s>>= 32
r3 = *(u64 *)(r1 +80)
r0 = r2
r0 += 8
if r3 > r0 goto pc+1
and this will cause verification failure since "r2 <<= 32" is not allowed
as "r2" is a packet pointer.
To fix this issue for case
r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */
this patch added additional checking in is_valid_access() callback
function for packet data/data_end/data_meta access. If those accesses
are with sign-extenstion, the verification will fail.
[1] https://lore.kernel.org/bpf/000000000000c90eee061d236d37@google.com/
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
bpf, lsm: Add check for BPF LSM return value
A bpf prog returning a positive number attached to file_alloc_security
hook makes kernel panic.
This happens because file system can not filter out the positive number
returned by the LSM prog using IS_ERR, and misinterprets this positive
number as a file pointer.
Given that hook file_alloc_security never returned positive number
before the introduction of BPF LSM, and other BPF LSM hooks may
encounter similar issues, this patch adds LSM return value check
in verifier, to ensure no unexpected value is returned.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Check link_res->hpo_dp_link_enc before using it
[WHAT & HOW]
Functions dp_enable_link_phy and dp_disable_link_phy can pass link_res
without initializing hpo_dp_link_enc and it is necessary to check for
null before dereferencing.
This fixes 2 FORWARD_NULL issues reported by Coverity.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
f2fs: check discard support for conventional zones
As the helper function f2fs_bdev_support_discard() shows, f2fs checks if
the target block devices support discard by calling
bdev_max_discard_sectors() and bdev_is_zoned(). This check works well
for most cases, but it does not work for conventional zones on zoned
block devices. F2fs assumes that zoned block devices support discard,
and calls __submit_discard_cmd(). When __submit_discard_cmd() is called
for sequential write required zones, it works fine since
__submit_discard_cmd() issues zone reset commands instead of discard
commands. However, when __submit_discard_cmd() is called for
conventional zones, __blkdev_issue_discard() is called even when the
devices do not support discard.
The inappropriate __blkdev_issue_discard() call was not a problem before
the commit 30f1e7241422 ("block: move discard checks into the ioctl
handler") because __blkdev_issue_discard() checked if the target devices
support discard or not. If not, it returned EOPNOTSUPP. After the
commit, __blkdev_issue_discard() no longer checks it. It always returns
zero and sets NULL to the given bio pointer. This NULL pointer triggers
f2fs_bug_on() in __submit_discard_cmd(). The BUG is recreated with the
commands below at the umount step, where /dev/nullb0 is a zoned null_blk
with 5GB total size, 128MB zone size and 10 conventional zones.
$ mkfs.f2fs -f -m /dev/nullb0
$ mount /dev/nullb0 /mnt
$ for ((i=0;i<5;i++)); do dd if=/dev/zero of=/mnt/test bs=65536 count=1600 conv=fsync; done
$ umount /mnt
To fix the BUG, avoid the inappropriate __blkdev_issue_discard() call.
When discard is requested for conventional zones, check if the device
supports discard or not. If not, return EOPNOTSUPP.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7996: fix NULL pointer dereference in mt7996_mcu_sta_bfer_he
Fix the NULL pointer dereference in mt7996_mcu_sta_bfer_he
routine adding an sta interface to the mt7996 driver.
Found by code review.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
scsi: sd: Fix off-by-one error in sd_read_block_characteristics()
Ff the device returns page 0xb1 with length 8 (happens with qemu v2.x, for
example), sd_read_block_characteristics() may attempt an out-of-bounds
memory access when accessing the zoned field at offset 8.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Skip Recompute DSC Params if no Stream on Link
[why]
Encounter NULL pointer dereference uner mst + dsc setup.
BUG: kernel NULL pointer dereference, address: 0000000000000008
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 4 PID: 917 Comm: sway Not tainted 6.3.9-arch1-1 #1 124dc55df4f5272ccb409f39ef4872fc2b3376a2
Hardware name: LENOVO 20NKS01Y00/20NKS01Y00, BIOS R12ET61W(1.31 ) 07/28/2022
RIP: 0010:drm_dp_atomic_find_time_slots+0x5e/0x260 [drm_display_helper]
Code: 01 00 00 48 8b 85 60 05 00 00 48 63 80 88 00 00 00 3b 43 28 0f 8d 2e 01 00 00 48 8b 53 30 48 8d 04 80 48 8d 04 c2 48 8b 40 18 <48> 8>
RSP: 0018:ffff960cc2df77d8 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff8afb87e81280 RCX: 0000000000000224
RDX: ffff8afb9ee37c00 RSI: ffff8afb8da1a578 RDI: ffff8afb87e81280
RBP: ffff8afb83d67000 R08: 0000000000000001 R09: ffff8afb9652f850
R10: ffff960cc2df7908 R11: 0000000000000002 R12: 0000000000000000
R13: ffff8afb8d7688a0 R14: ffff8afb8da1a578 R15: 0000000000000224
FS: 00007f4dac35ce00(0000) GS:ffff8afe30b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 000000010ddc6000 CR4: 00000000003506e0
Call Trace:
<TASK>
? __die+0x23/0x70
? page_fault_oops+0x171/0x4e0
? plist_add+0xbe/0x100
? exc_page_fault+0x7c/0x180
? asm_exc_page_fault+0x26/0x30
? drm_dp_atomic_find_time_slots+0x5e/0x260 [drm_display_helper 0e67723696438d8e02b741593dd50d80b44c2026]
? drm_dp_atomic_find_time_slots+0x28/0x260 [drm_display_helper 0e67723696438d8e02b741593dd50d80b44c2026]
compute_mst_dsc_configs_for_link+0x2ff/0xa40 [amdgpu 62e600d2a75e9158e1cd0a243bdc8e6da040c054]
? fill_plane_buffer_attributes+0x419/0x510 [amdgpu 62e600d2a75e9158e1cd0a243bdc8e6da040c054]
compute_mst_dsc_configs_for_state+0x1e1/0x250 [amdgpu 62e600d2a75e9158e1cd0a243bdc8e6da040c054]
amdgpu_dm_atomic_check+0xecd/0x1190 [amdgpu 62e600d2a75e9158e1cd0a243bdc8e6da040c054]
drm_atomic_check_only+0x5c5/0xa40
drm_mode_atomic_ioctl+0x76e/0xbc0
[how]
dsc recompute should be skipped if no mode change detected on the new
request. If detected, keep checking whether the stream is already on
current state or not.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-21