Linux: >> Linux Kernel >> 2.6.15.4 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
misc: ibmasm: fix OOB MMIO read in ibmasm_handle_mouse_interrupt()
ibmasm_handle_mouse_interrupt() performs an out-of-bounds MMIO read
when the queue reader or writer index from hardware exceeds
REMOTE_QUEUE_SIZE (60).
A compromised service processor can trigger this by writing an
out-of-range value to the reader or writer MMIO register before
asserting an interrupt. Since writer is re-read from hardware on
every loop iteration, it can also be set to an out-of-range value
after the loop has already started.
The root cause is that get_queue_reader() and get_queue_writer() return
raw readl() values that are passed directly into get_queue_entry(),
which computes:
queue_begin + reader * sizeof(struct remote_input)
with no bounds check. This unchecked MMIO address is then passed to
memcpy_fromio(), reading 8 bytes from unintended device registers.
For sufficiently large values the address falls outside the PCI BAR
mapping entirely, triggering a machine check exception.
Fix by checking both indices against REMOTE_QUEUE_SIZE at the top of
the loop body, before any call to get_queue_entry(). On an out-of-range
value, reset the reader register to 0 via set_queue_reader() before
breaking, so that normal queue operation can resume if the corrupted
hardware state is transient.
CVSS Score
7.1
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
dm mirror: fix integer overflow in create_dirty_log()
The argument count calculation in create_dirty_log() performs
`*args_used = 2 + param_count` before validating against argc. When a
user provides a param_count close to UINT_MAX via the device mapper
table string, this unsigned addition wraps around to a small value,
causing the subsequent `argc < *args_used` check to be bypassed.
The overflowed param_count is then passed as argc to dm_dirty_log_create(),
where it can cause out-of-bounds reads on the argv array.
Fix by comparing param_count against argc - 2 before performing the
addition, following the same pattern used by parse_features() in the
same file. Since argc >= 2 is already guaranteed, the subtraction is
safe.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
ext2: reject inodes with zero i_nlink and valid mode in ext2_iget()
ext2_iget() already rejects inodes with i_nlink == 0 when i_mode is
zero or i_dtime is set, treating them as deleted. However, the case of
i_nlink == 0 with a non-zero mode and zero dtime slips through. Since
ext2 has no orphan list, such a combination can only result from
filesystem corruption - a legitimate inode deletion always sets either
i_dtime or clears i_mode before freeing the inode.
A crafted image can exploit this gap to present such an inode to the
VFS, which then triggers WARN_ON inside drop_nlink() (fs/inode.c) via
ext2_unlink(), ext2_rename() and ext2_rmdir():
WARNING: CPU: 3 PID: 609 at fs/inode.c:336 drop_nlink+0xad/0xd0 fs/inode.c:336
CPU: 3 UID: 0 PID: 609 Comm: syz-executor Not tainted 6.12.77+ #1
Call Trace:
<TASK>
inode_dec_link_count include/linux/fs.h:2518 [inline]
ext2_unlink+0x26c/0x300 fs/ext2/namei.c:295
vfs_unlink+0x2fc/0x9b0 fs/namei.c:4477
do_unlinkat+0x53e/0x730 fs/namei.c:4541
__x64_sys_unlink+0xc6/0x110 fs/namei.c:4587
do_syscall_64+0xf5/0x220 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
WARNING: CPU: 0 PID: 646 at fs/inode.c:336 drop_nlink+0xad/0xd0 fs/inode.c:336
CPU: 0 UID: 0 PID: 646 Comm: syz.0.17 Not tainted 6.12.77+ #1
Call Trace:
<TASK>
inode_dec_link_count include/linux/fs.h:2518 [inline]
ext2_rename+0x35e/0x850 fs/ext2/namei.c:374
vfs_rename+0xf2f/0x2060 fs/namei.c:5021
do_renameat2+0xbe2/0xd50 fs/namei.c:5178
__x64_sys_rename+0x7e/0xa0 fs/namei.c:5223
do_syscall_64+0xf5/0x220 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
WARNING: CPU: 0 PID: 634 at fs/inode.c:336 drop_nlink+0xad/0xd0 fs/inode.c:336
CPU: 0 UID: 0 PID: 634 Comm: syz-executor Not tainted 6.12.77+ #1
Call Trace:
<TASK>
inode_dec_link_count include/linux/fs.h:2518 [inline]
ext2_rmdir+0xca/0x110 fs/ext2/namei.c:311
vfs_rmdir+0x204/0x690 fs/namei.c:4348
do_rmdir+0x372/0x3e0 fs/namei.c:4407
__x64_sys_unlinkat+0xf0/0x130 fs/namei.c:4577
do_syscall_64+0xf5/0x220 arch/x86/entry/common.c:78
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
Extend the existing i_nlink == 0 check to also catch this case,
reporting the corruption via ext2_error() and returning -EFSCORRUPTED.
This rejects the inode at load time and prevents it from reaching any
of the namei.c paths.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
ibmasm: fix OOB reads in command_file_write due to missing size checks
The command_file_write() handler allocates a kernel buffer of exactly
count bytes and copies user data into it, but does not validate the
buffer against the dot command protocol before passing it to
get_dot_command_size() and get_dot_command_timeout().
Since both the allocation size (count) and the header fields (command_size,
data_size) are independently user-controlled, an attacker can cause
get_dot_command_size() to return a value exceeding the allocation,
triggering OOB reads in get_dot_command_timeout() and an out-of-bounds
memcpy_toio() that leaks kernel heap memory to the service processor.
Fix with two guards: reject writes smaller than sizeof(struct
dot_command_header) before allocation, then after copying user data
reject commands where the buffer is smaller than the total size declared
by the header (sizeof(header) + command_size + data_size). This ensures
all subsequent header and payload field accesses stay within the buffer.
CVSS Score
7.1
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
usb: image: mdc800: kill download URB on timeout
mdc800_device_read() submits download_urb and waits for completion.
If the timeout fires and the device has not responded, the function
returns without killing the URB, leaving it active.
A subsequent read() resubmits the same URB while it is still
in-flight, triggering the WARN in usb_submit_urb():
"URB submitted while active"
Check the return value of wait_event_timeout() and kill the URB if
it indicates timeout, ensuring the URB is complete before its status
is inspected or the URB is resubmitted.
Similar to
- commit 372c93131998 ("USB: yurex: fix control-URB timeout handling")
- commit b98d5000c505 ("media: rc: iguanair: handle timeouts")
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
USB: core: Limit the length of unkillable synchronous timeouts
The usb_control_msg(), usb_bulk_msg(), and usb_interrupt_msg() APIs in
usbcore allow unlimited timeout durations. And since they use
uninterruptible waits, this leaves open the possibility of hanging a
task for an indefinitely long time, with no way to kill it short of
unplugging the target device.
To prevent this sort of problem, enforce a maximum limit on the length
of these unkillable timeouts. The limit chosen here, somewhat
arbitrarily, is 60 seconds. On many systems (although not all) this
is short enough to avoid triggering the kernel's hung-task detector.
In addition, clear up the ambiguity of negative timeout values by
treating them the same as 0, i.e., using the maximum allowed timeout.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
ACPI: processor: Fix NULL-pointer dereference in acpi_processor_errata_piix4()
In acpi_processor_errata_piix4(), the pointer dev is first assigned an IDE
device and then reassigned an ISA device:
dev = pci_get_subsys(..., PCI_DEVICE_ID_INTEL_82371AB, ...);
dev = pci_get_subsys(..., PCI_DEVICE_ID_INTEL_82371AB_0, ...);
If the first lookup succeeds but the second fails, dev becomes NULL. This
leads to a potential null-pointer dereference when dev_dbg() is called:
if (errata.piix4.bmisx)
dev_dbg(&dev->dev, ...);
To prevent this, use two temporary pointers and retrieve each device
independently, avoiding overwriting dev with a possible NULL value.
[ rjw: Subject adjustment, added an empty code line ]
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
hfsplus: pretend special inodes as regular files
Since commit af153bb63a33 ("vfs: catch invalid modes in may_open()")
requires any inode be one of S_IFDIR/S_IFLNK/S_IFREG/S_IFCHR/S_IFBLK/
S_IFIFO/S_IFSOCK type, use S_IFREG for special inodes.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
minix: Add required sanity checking to minix_check_superblock()
The fs/minix implementation of the minix filesystem does not currently
support any other value for s_log_zone_size than 0. This is also the
only value supported in util-linux; see mkfs.minix.c line 511. In
addition, this patch adds some sanity checking for the other minix
superblock fields, and moves the minix_blocks_needed() checks for the
zmap and imap also to minix_check_super_block().
This also closes a related syzbot bug report.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-06
In the Linux kernel, the following vulnerability has been resolved:
atm: fore200e: fix use-after-free in tasklets during device removal
When the PCA-200E or SBA-200E adapter is being detached, the fore200e
is deallocated. However, the tx_tasklet or rx_tasklet may still be running
or pending, leading to use-after-free bug when the already freed fore200e
is accessed again in fore200e_tx_tasklet() or fore200e_rx_tasklet().
One of the race conditions can occur as follows:
CPU 0 (cleanup) | CPU 1 (tasklet)
fore200e_pca_remove_one() | fore200e_interrupt()
fore200e_shutdown() | tasklet_schedule()
kfree(fore200e) | fore200e_tx_tasklet()
| fore200e-> // UAF
Fix this by ensuring tx_tasklet or rx_tasklet is properly canceled before
the fore200e is released. Add tasklet_kill() in fore200e_shutdown() to
synchronize with any pending or running tasklets. Moreover, since
fore200e_reset() could prevent further interrupts or data transfers,
the tasklet_kill() should be placed after fore200e_reset() to prevent
the tasklet from being rescheduled in fore200e_interrupt(). Finally,
it only needs to do tasklet_kill() when the fore200e state is greater
than or equal to FORE200E_STATE_IRQ, since tasklets are uninitialized
in earlier states. In a word, the tasklet_kill() should be placed in
the FORE200E_STATE_IRQ branch within the switch...case structure.
This bug was identified through static analysis.
CVSS Score
7.5
EPSS Score
0.004
Published
2026-05-06