Linux: >> Linux Kernel >> 6.6.48 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
HSI: ssi_protocol: Fix use after free vulnerability in ssi_protocol Driver Due to Race Condition
In the ssi_protocol_probe() function, &ssi->work is bound with
ssip_xmit_work(), In ssip_pn_setup(), the ssip_pn_xmit() function
within the ssip_pn_ops structure is capable of starting the
work.
If we remove the module which will call ssi_protocol_remove()
to make a cleanup, it will free ssi through kfree(ssi),
while the work mentioned above will be used. The sequence
of operations that may lead to a UAF bug is as follows:
CPU0 CPU1
| ssip_xmit_work
ssi_protocol_remove |
kfree(ssi); |
| struct hsi_client *cl = ssi->cl;
| // use ssi
Fix it by ensuring that the work is canceled before proceeding
with the cleanup in ssi_protocol_remove().
CVSS Score
7.8
EPSS Score
0.0
Published
2025-04-18
In the Linux kernel, the following vulnerability has been resolved:
io_uring: fix io_req_prep_async with provided buffers
io_req_prep_async() can import provided buffers, commit the ring state
by giving up on that before, it'll be reimported later if needed.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-04-18
In the Linux kernel, the following vulnerability has been resolved:
clk: samsung: Fix UBSAN panic in samsung_clk_init()
With UBSAN_ARRAY_BOUNDS=y, I'm hitting the below panic due to
dereferencing `ctx->clk_data.hws` before setting
`ctx->clk_data.num = nr_clks`. Move that up to fix the crash.
UBSAN: array index out of bounds: 00000000f2005512 [#1] PREEMPT SMP
<snip>
Call trace:
samsung_clk_init+0x110/0x124 (P)
samsung_clk_init+0x48/0x124 (L)
samsung_cmu_register_one+0x3c/0xa0
exynos_arm64_register_cmu+0x54/0x64
__gs101_cmu_top_of_clk_init_declare+0x28/0x60
...
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-18
In the Linux kernel, the following vulnerability has been resolved:
x86/mce: use is_copy_from_user() to determine copy-from-user context
Patch series "mm/hwpoison: Fix regressions in memory failure handling",
v4.
## 1. What am I trying to do:
This patchset resolves two critical regressions related to memory failure
handling that have appeared in the upstream kernel since version 5.17, as
compared to 5.10 LTS.
- copyin case: poison found in user page while kernel copying from user space
- instr case: poison found while instruction fetching in user space
## 2. What is the expected outcome and why
- For copyin case:
Kernel can recover from poison found where kernel is doing get_user() or
copy_from_user() if those places get an error return and the kernel return
-EFAULT to the process instead of crashing. More specifily, MCE handler
checks the fixup handler type to decide whether an in kernel #MC can be
recovered. When EX_TYPE_UACCESS is found, the PC jumps to recovery code
specified in _ASM_EXTABLE_FAULT() and return a -EFAULT to user space.
- For instr case:
If a poison found while instruction fetching in user space, full recovery
is possible. User process takes #PF, Linux allocates a new page and fills
by reading from storage.
## 3. What actually happens and why
- For copyin case: kernel panic since v5.17
Commit 4c132d1d844a ("x86/futex: Remove .fixup usage") introduced a new
extable fixup type, EX_TYPE_EFAULT_REG, and later patches updated the
extable fixup type for copy-from-user operations, changing it from
EX_TYPE_UACCESS to EX_TYPE_EFAULT_REG. It breaks previous EX_TYPE_UACCESS
handling when posion found in get_user() or copy_from_user().
- For instr case: user process is killed by a SIGBUS signal due to #CMCI
and #MCE race
When an uncorrected memory error is consumed there is a race between the
CMCI from the memory controller reporting an uncorrected error with a UCNA
signature, and the core reporting and SRAR signature machine check when
the data is about to be consumed.
### Background: why *UN*corrected errors tied to *C*MCI in Intel platform [1]
Prior to Icelake memory controllers reported patrol scrub events that
detected a previously unseen uncorrected error in memory by signaling a
broadcast machine check with an SRAO (Software Recoverable Action
Optional) signature in the machine check bank. This was overkill because
it's not an urgent problem that no core is on the verge of consuming that
bad data. It's also found that multi SRAO UCE may cause nested MCE
interrupts and finally become an IERR.
Hence, Intel downgrades the machine check bank signature of patrol scrub
from SRAO to UCNA (Uncorrected, No Action required), and signal changed to
#CMCI. Just to add to the confusion, Linux does take an action (in
uc_decode_notifier()) to try to offline the page despite the UC*NA*
signature name.
### Background: why #CMCI and #MCE race when poison is consuming in
Intel platform [1]
Having decided that CMCI/UCNA is the best action for patrol scrub errors,
the memory controller uses it for reads too. But the memory controller is
executing asynchronously from the core, and can't tell the difference
between a "real" read and a speculative read. So it will do CMCI/UCNA if
an error is found in any read.
Thus:
1) Core is clever and thinks address A is needed soon, issues a
speculative read.
2) Core finds it is going to use address A soon after sending the read
request
3) The CMCI from the memory controller is in a race with MCE from the
core that will soon try to retire the load from address A.
Quite often (because speculation has got better) the CMCI from the memory
controller is delivered before the core is committed to the instruction
reading address A, so the interrupt is taken, and Linux offlines the page
(marking it as poison).
## Why user process is killed for instr case
Commit 046545a661af ("mm/hwpoison: fix error page recovered but reported
"not
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-18
In the Linux kernel, the following vulnerability has been resolved:
md/raid10: wait barrier before returning discard request with REQ_NOWAIT
raid10_handle_discard should wait barrier before returning a discard bio
which has REQ_NOWAIT. And there is no need to print warning calltrace
if a discard bio has REQ_NOWAIT flag. Quality engineer usually checks
dmesg and reports error if dmesg has warning/error calltrace.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-18
In the Linux kernel, the following vulnerability has been resolved:
jfs: reject on-disk inodes of an unsupported type
Syzbot has reported the following BUG:
kernel BUG at fs/inode.c:668!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 3 UID: 0 PID: 139 Comm: jfsCommit Not tainted 6.12.0-rc4-syzkaller-00085-g4e46774408d9 #0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014
RIP: 0010:clear_inode+0x168/0x190
Code: 4c 89 f7 e8 ba fe e5 ff e9 61 ff ff ff 44 89 f1 80 e1 07 80 c1 03 38 c1 7c c1 4c 89 f7 e8 90 ff e5 ff eb b7
0b e8 01 5d 7f ff 90 0f 0b e8 f9 5c 7f ff 90 0f 0b e8 f1 5c 7f
RSP: 0018:ffffc900027dfae8 EFLAGS: 00010093
RAX: ffffffff82157a87 RBX: 0000000000000001 RCX: ffff888104d4b980
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900027dfc90 R08: ffffffff82157977 R09: fffff520004fbf38
R10: dffffc0000000000 R11: fffff520004fbf38 R12: dffffc0000000000
R13: ffff88811315bc00 R14: ffff88811315bda8 R15: ffff88811315bb80
FS: 0000000000000000(0000) GS:ffff888135f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005565222e0578 CR3: 0000000026ef0000 CR4: 00000000000006f0
Call Trace:
<TASK>
? __die_body+0x5f/0xb0
? die+0x9e/0xc0
? do_trap+0x15a/0x3a0
? clear_inode+0x168/0x190
? do_error_trap+0x1dc/0x2c0
? clear_inode+0x168/0x190
? __pfx_do_error_trap+0x10/0x10
? report_bug+0x3cd/0x500
? handle_invalid_op+0x34/0x40
? clear_inode+0x168/0x190
? exc_invalid_op+0x38/0x50
? asm_exc_invalid_op+0x1a/0x20
? clear_inode+0x57/0x190
? clear_inode+0x167/0x190
? clear_inode+0x168/0x190
? clear_inode+0x167/0x190
jfs_evict_inode+0xb5/0x440
? __pfx_jfs_evict_inode+0x10/0x10
evict+0x4ea/0x9b0
? __pfx_evict+0x10/0x10
? iput+0x713/0xa50
txUpdateMap+0x931/0xb10
? __pfx_txUpdateMap+0x10/0x10
jfs_lazycommit+0x49a/0xb80
? _raw_spin_unlock_irqrestore+0x8f/0x140
? lockdep_hardirqs_on+0x99/0x150
? __pfx_jfs_lazycommit+0x10/0x10
? __pfx_default_wake_function+0x10/0x10
? __kthread_parkme+0x169/0x1d0
? __pfx_jfs_lazycommit+0x10/0x10
kthread+0x2f2/0x390
? __pfx_jfs_lazycommit+0x10/0x10
? __pfx_kthread+0x10/0x10
ret_from_fork+0x4d/0x80
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
This happens when 'clear_inode()' makes an attempt to finalize an underlying
JFS inode of unknown type. According to JFS layout description from
https://jfs.sourceforge.net/project/pub/jfslayout.pdf, inode types from 5 to
15 are reserved for future extensions and should not be encountered on a valid
filesystem. So add an extra check for valid inode type in 'copy_from_dinode()'.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-18
In the Linux kernel, the following vulnerability has been resolved:
remoteproc: core: Clear table_sz when rproc_shutdown
There is case as below could trigger kernel dump:
Use U-Boot to start remote processor(rproc) with resource table
published to a fixed address by rproc. After Kernel boots up,
stop the rproc, load a new firmware which doesn't have resource table
,and start rproc.
When starting rproc with a firmware not have resource table,
`memcpy(loaded_table, rproc->cached_table, rproc->table_sz)` will
trigger dump, because rproc->cache_table is set to NULL during the last
stop operation, but rproc->table_sz is still valid.
This issue is found on i.MX8MP and i.MX9.
Dump as below:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
Mem abort info:
ESR = 0x0000000096000004
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x04: level 0 translation fault
Data abort info:
ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
user pgtable: 4k pages, 48-bit VAs, pgdp=000000010af63000
[0000000000000000] pgd=0000000000000000, p4d=0000000000000000
Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 2 UID: 0 PID: 1060 Comm: sh Not tainted 6.14.0-rc7-next-20250317-dirty #38
Hardware name: NXP i.MX8MPlus EVK board (DT)
pstate: a0000005 (NzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __pi_memcpy_generic+0x110/0x22c
lr : rproc_start+0x88/0x1e0
Call trace:
__pi_memcpy_generic+0x110/0x22c (P)
rproc_boot+0x198/0x57c
state_store+0x40/0x104
dev_attr_store+0x18/0x2c
sysfs_kf_write+0x7c/0x94
kernfs_fop_write_iter+0x120/0x1cc
vfs_write+0x240/0x378
ksys_write+0x70/0x108
__arm64_sys_write+0x1c/0x28
invoke_syscall+0x48/0x10c
el0_svc_common.constprop.0+0xc0/0xe0
do_el0_svc+0x1c/0x28
el0_svc+0x30/0xcc
el0t_64_sync_handler+0x10c/0x138
el0t_64_sync+0x198/0x19c
Clear rproc->table_sz to address the issue.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-18
In the Linux kernel, the following vulnerability has been resolved:
drm/mediatek: dp: drm_err => dev_err in HPD path to avoid NULL ptr
The function mtk_dp_wait_hpd_asserted() may be called before the
`mtk_dp->drm_dev` pointer is assigned in mtk_dp_bridge_attach().
Specifically it can be called via this callpath:
- mtk_edp_wait_hpd_asserted
- [panel probe]
- dp_aux_ep_probe
Using "drm" level prints anywhere in this callpath causes a NULL
pointer dereference. Change the error message directly in
mtk_dp_wait_hpd_asserted() to dev_err() to avoid this. Also change the
error messages in mtk_dp_parse_capabilities(), which is called by
mtk_dp_wait_hpd_asserted().
While touching these prints, also add the error code to them to make
future debugging easier.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-18
In the Linux kernel, the following vulnerability has been resolved:
net_sched: skbprio: Remove overly strict queue assertions
In the current implementation, skbprio enqueue/dequeue contains an assertion
that fails under certain conditions when SKBPRIO is used as a child qdisc under
TBF with specific parameters. The failure occurs because TBF sometimes peeks at
packets in the child qdisc without actually dequeuing them when tokens are
unavailable.
This peek operation creates a discrepancy between the parent and child qdisc
queue length counters. When TBF later receives a high-priority packet,
SKBPRIO's queue length may show a different value than what's reflected in its
internal priority queue tracking, triggering the assertion.
The fix removes this overly strict assertions in SKBPRIO, they are not
necessary at all.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-04-18
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix OOB read when checking dotdot dir
Mounting a corrupted filesystem with directory which contains '.' dir
entry with rec_len == block size results in out-of-bounds read (later
on, when the corrupted directory is removed).
ext4_empty_dir() assumes every ext4 directory contains at least '.'
and '..' as directory entries in the first data block. It first loads
the '.' dir entry, performs sanity checks by calling ext4_check_dir_entry()
and then uses its rec_len member to compute the location of '..' dir
entry (in ext4_next_entry). It assumes the '..' dir entry fits into the
same data block.
If the rec_len of '.' is precisely one block (4KB), it slips through the
sanity checks (it is considered the last directory entry in the data
block) and leaves "struct ext4_dir_entry_2 *de" point exactly past the
memory slot allocated to the data block. The following call to
ext4_check_dir_entry() on new value of de then dereferences this pointer
which results in out-of-bounds mem access.
Fix this by extending __ext4_check_dir_entry() to check for '.' dir
entries that reach the end of data block. Make sure to ignore the phony
dir entries for checksum (by checking name_len for non-zero).
Note: This is reported by KASAN as use-after-free in case another
structure was recently freed from the slot past the bound, but it is
really an OOB read.
This issue was found by syzkaller tool.
Call Trace:
[ 38.594108] BUG: KASAN: slab-use-after-free in __ext4_check_dir_entry+0x67e/0x710
[ 38.594649] Read of size 2 at addr ffff88802b41a004 by task syz-executor/5375
[ 38.595158]
[ 38.595288] CPU: 0 UID: 0 PID: 5375 Comm: syz-executor Not tainted 6.14.0-rc7 #1
[ 38.595298] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 38.595304] Call Trace:
[ 38.595308] <TASK>
[ 38.595311] dump_stack_lvl+0xa7/0xd0
[ 38.595325] print_address_description.constprop.0+0x2c/0x3f0
[ 38.595339] ? __ext4_check_dir_entry+0x67e/0x710
[ 38.595349] print_report+0xaa/0x250
[ 38.595359] ? __ext4_check_dir_entry+0x67e/0x710
[ 38.595368] ? kasan_addr_to_slab+0x9/0x90
[ 38.595378] kasan_report+0xab/0xe0
[ 38.595389] ? __ext4_check_dir_entry+0x67e/0x710
[ 38.595400] __ext4_check_dir_entry+0x67e/0x710
[ 38.595410] ext4_empty_dir+0x465/0x990
[ 38.595421] ? __pfx_ext4_empty_dir+0x10/0x10
[ 38.595432] ext4_rmdir.part.0+0x29a/0xd10
[ 38.595441] ? __dquot_initialize+0x2a7/0xbf0
[ 38.595455] ? __pfx_ext4_rmdir.part.0+0x10/0x10
[ 38.595464] ? __pfx___dquot_initialize+0x10/0x10
[ 38.595478] ? down_write+0xdb/0x140
[ 38.595487] ? __pfx_down_write+0x10/0x10
[ 38.595497] ext4_rmdir+0xee/0x140
[ 38.595506] vfs_rmdir+0x209/0x670
[ 38.595517] ? lookup_one_qstr_excl+0x3b/0x190
[ 38.595529] do_rmdir+0x363/0x3c0
[ 38.595537] ? __pfx_do_rmdir+0x10/0x10
[ 38.595544] ? strncpy_from_user+0x1ff/0x2e0
[ 38.595561] __x64_sys_unlinkat+0xf0/0x130
[ 38.595570] do_syscall_64+0x5b/0x180
[ 38.595583] entry_SYSCALL_64_after_hwframe+0x76/0x7e
CVSS Score
7.1
EPSS Score
0.0
Published
2025-04-18