In the Linux kernel, the following vulnerability has been resolved:
perf: Fix refcount warning on event->mmap_count increment
When calling refcount_inc(&event->mmap_count) inside perf_mmap_rb(), the
following warning is triggered:
refcount_t: addition on 0; use-after-free.
WARNING: lib/refcount.c:25
PoC:
struct perf_event_attr attr = {0};
int fd = syscall(__NR_perf_event_open, &attr, 0, -1, -1, 0);
mmap(NULL, 0x3000, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
int victim = syscall(__NR_perf_event_open, &attr, 0, -1, fd,
PERF_FLAG_FD_OUTPUT);
mmap(NULL, 0x3000, PROT_READ | PROT_WRITE, MAP_SHARED, victim, 0);
This occurs when creating a group member event with the flag
PERF_FLAG_FD_OUTPUT. The group leader should be mmap-ed and then mmap-ing
the event triggers the warning.
Since the event has copied the output_event in perf_event_set_output(),
event->rb is set. As a result, perf_mmap_rb() calls
refcount_inc(&event->mmap_count) when event->mmap_count = 0.
Disallow the case when event->mmap_count = 0. This also prevents two
events from updating the same user_page.
In the Linux kernel, the following vulnerability has been resolved:
io_uring/io-wq: check IO_WQ_BIT_EXIT inside work run loop
Currently this is checked before running the pending work. Normally this
is quite fine, as work items either end up blocking (which will create a
new worker for other items), or they complete fairly quickly. But syzbot
reports an issue where io-wq takes seemingly forever to exit, and with a
bit of debugging, this turns out to be because it queues a bunch of big
(2GB - 4096b) reads with a /dev/msr* file. Since this file type doesn't
support ->read_iter(), loop_rw_iter() ends up handling them. Each read
returns 16MB of data read, which takes 20 (!!) seconds. With a bunch of
these pending, processing the whole chain can take a long time. Easily
longer than the syzbot uninterruptible sleep timeout of 140 seconds.
This then triggers a complaint off the io-wq exit path:
INFO: task syz.4.135:6326 blocked for more than 143 seconds.
Not tainted syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.135 state:D stack:26824 pid:6326 tgid:6324 ppid:5957 task_flags:0x400548 flags:0x00080000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121
io_wq_exit_workers io_uring/io-wq.c:1328 [inline]
io_wq_put_and_exit+0x271/0x8a0 io_uring/io-wq.c:1356
io_uring_clean_tctx+0x10d/0x190 io_uring/tctx.c:203
io_uring_cancel_generic+0x69c/0x9a0 io_uring/cancel.c:651
io_uring_files_cancel include/linux/io_uring.h:19 [inline]
do_exit+0x2ce/0x2bd0 kernel/exit.c:911
do_group_exit+0xd3/0x2a0 kernel/exit.c:1112
get_signal+0x2671/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa02738f749
RSP: 002b:00007fa0281ae0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fa0275e6098 RCX: 00007fa02738f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa0275e6098
RBP: 00007fa0275e6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa0275e6128 R14: 00007fff14e4fcb0 R15: 00007fff14e4fd98
There's really nothing wrong here, outside of processing these reads
will take a LONG time. However, we can speed up the exit by checking the
IO_WQ_BIT_EXIT inside the io_worker_handle_work() loop, as syzbot will
exit the ring after queueing up all of these reads. Then once the first
item is processed, io-wq will simply cancel the rest. That should avoid
syzbot running into this complaint again.
In the Linux kernel, the following vulnerability has been resolved:
arm64/fpsimd: ptrace: Fix SVE writes on !SME systems
When SVE is supported but SME is not supported, a ptrace write to the
NT_ARM_SVE regset can place the tracee into an invalid state where
(non-streaming) SVE register data is stored in FP_STATE_SVE format but
TIF_SVE is clear. This can result in a later warning from
fpsimd_restore_current_state(), e.g.
WARNING: CPU: 0 PID: 7214 at arch/arm64/kernel/fpsimd.c:383 fpsimd_restore_current_state+0x50c/0x748
When this happens, fpsimd_restore_current_state() will set TIF_SVE,
placing the task into the correct state. This occurs before any other
check of TIF_SVE can possibly occur, as other checks of TIF_SVE only
happen while the FPSIMD/SVE/SME state is live. Thus, aside from the
warning, there is no functional issue.
This bug was introduced during rework to error handling in commit:
9f8bf718f2923 ("arm64/fpsimd: ptrace: Gracefully handle errors")
... where the setting of TIF_SVE was moved into a block which is only
executed when system_supports_sme() is true.
Fix this by removing the system_supports_sme() check. This ensures that
TIF_SVE is set for (SVE-formatted) writes to NT_ARM_SVE, at the cost of
unconditionally manipulating the tracee's saved svcr value. The
manipulation of svcr is benign and inexpensive, and we already do
similar elsewhere (e.g. during signal handling), so I don't think it's
worth guarding this with system_supports_sme() checks.
Aside from the above, there is no functional change. The 'type' argument
to sve_set_common() is only set to ARM64_VEC_SME (in ssve_set())) when
system_supports_sme(), so the ARM64_VEC_SME case in the switch statement
is still unreachable when !system_supports_sme(). When
CONFIG_ARM64_SME=n, the only caller of sve_set_common() is sve_set(),
and the compiler can constant-fold for the case where type is
ARM64_VEC_SVE, removing the logic for other cases.
In the Linux kernel, the following vulnerability has been resolved:
serial: Fix not set tty->port race condition
Revert commit bfc467db60b7 ("serial: remove redundant
tty_port_link_device()") because the tty_port_link_device() is not
redundant: the tty->port has to be confured before we call
uart_configure_port(), otherwise user-space can open console without TTY
linked to the driver.
This tty_port_link_device() was added explicitly to avoid this exact
issue in commit fb2b90014d78 ("tty: link tty and port before configuring
it as console"), so offending commit basically reverted the fix saying
it is redundant without addressing the actual race condition presented
there.
Reproducible always as tty->port warning on Qualcomm SoC with most of
devices disabled, so with very fast boot, and one serial device being
the console:
printk: legacy console [ttyMSM0] enabled
printk: legacy console [ttyMSM0] enabled
printk: legacy bootconsole [qcom_geni0] disabled
printk: legacy bootconsole [qcom_geni0] disabled
------------[ cut here ]------------
tty_init_dev: ttyMSM driver does not set tty->port. This would crash the kernel. Fix the driver!
WARNING: drivers/tty/tty_io.c:1414 at tty_init_dev.part.0+0x228/0x25c, CPU#2: systemd/1
Modules linked in: socinfo tcsrcc_eliza gcc_eliza sm3_ce fuse ipv6
CPU: 2 UID: 0 PID: 1 Comm: systemd Tainted: G S 6.19.0-rc4-next-20260108-00024-g2202f4d30aa8 #73 PREEMPT
Tainted: [S]=CPU_OUT_OF_SPEC
Hardware name: Qualcomm Technologies, Inc. Eliza (DT)
...
tty_init_dev.part.0 (drivers/tty/tty_io.c:1414 (discriminator 11)) (P)
tty_open (arch/arm64/include/asm/atomic_ll_sc.h:95 (discriminator 3) drivers/tty/tty_io.c:2073 (discriminator 3) drivers/tty/tty_io.c:2120 (discriminator 3))
chrdev_open (fs/char_dev.c:411)
do_dentry_open (fs/open.c:962)
vfs_open (fs/open.c:1094)
do_open (fs/namei.c:4634)
path_openat (fs/namei.c:4793)
do_filp_open (fs/namei.c:4820)
do_sys_openat2 (fs/open.c:1391 (discriminator 3))
...
Starting Network Name Resolution...
Apparently the flow with this small Yocto-based ramdisk user-space is:
driver (qcom_geni_serial.c): user-space:
============================ ===========
qcom_geni_serial_probe()
uart_add_one_port()
serial_core_register_port()
serial_core_add_one_port()
uart_configure_port()
register_console()
|
| open console
| ...
| tty_init_dev()
| driver->ports[idx] is NULL
|
tty_port_register_device_attr_serdev()
tty_port_link_device() <- set driver->ports[idx]
In the Linux kernel, the following vulnerability has been resolved:
pmdomain: imx8m-blk-ctrl: Remove separate rst and clk mask for 8mq vpu
For i.MX8MQ platform, the ADB in the VPUMIX domain has no separate reset
and clock enable bits, but is ungated and reset together with the VPUs.
So we can't reset G1 or G2 separately, it may led to the system hang.
Remove rst_mask and clk_mask of imx8mq_vpu_blk_ctl_domain_data.
Let imx8mq_vpu_power_notifier() do really vpu reset.
In the Linux kernel, the following vulnerability has been resolved:
ice: add missing ice_deinit_hw() in devlink reinit path
devlink-reload results in ice_init_hw failed error, and then removing
the ice driver causes a NULL pointer dereference.
[ +0.102213] ice 0000:ca:00.0: ice_init_hw failed: -16
...
[ +0.000001] Call Trace:
[ +0.000003] <TASK>
[ +0.000006] ice_unload+0x8f/0x100 [ice]
[ +0.000081] ice_remove+0xba/0x300 [ice]
Commit 1390b8b3d2be ("ice: remove duplicate call to ice_deinit_hw() on
error paths") removed ice_deinit_hw() from ice_deinit_dev(). As a result
ice_devlink_reinit_down() no longer calls ice_deinit_hw(), but
ice_devlink_reinit_up() still calls ice_init_hw(). Since the control
queues are not uninitialized, ice_init_hw() fails with -EBUSY.
Add ice_deinit_hw() to ice_devlink_reinit_down() to correspond with
ice_init_hw() in ice_devlink_reinit_up().
In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix data-race warning and potential load/store tearing
Fix the following:
BUG: KCSAN: data-race in rxrpc_peer_keepalive_worker / rxrpc_send_data_packet
which is reporting an issue with the reads and writes to ->last_tx_at in:
conn->peer->last_tx_at = ktime_get_seconds();
and:
keepalive_at = peer->last_tx_at + RXRPC_KEEPALIVE_TIME;
The lockless accesses to these to values aren't actually a problem as the
read only needs an approximate time of last transmission for the purposes
of deciding whether or not the transmission of a keepalive packet is
warranted yet.
Also, as ->last_tx_at is a 64-bit value, tearing can occur on a 32-bit
arch.
Fix both of these by switching to an unsigned int for ->last_tx_at and only
storing the LSW of the time64_t. It can then be reconstructed at need
provided no more than 68 years has elapsed since the last transmission.
In the Linux kernel, the following vulnerability has been resolved:
mmc: sdhci-of-dwcmshc: Prevent illegal clock reduction in HS200/HS400 mode
When operating in HS200 or HS400 timing modes, reducing the clock frequency
below 52MHz will lead to link broken as the Rockchip DWC MSHC controller
requires maintaining a minimum clock of 52MHz in these modes.
Add a check to prevent illegal clock reduction through debugfs:
root@debian:/# echo 50000000 > /sys/kernel/debug/mmc0/clock
root@debian:/# [ 30.090146] mmc0: running CQE recovery
mmc0: cqhci: Failed to halt
mmc0: cqhci: spurious TCN for tag 0
WARNING: drivers/mmc/host/cqhci-core.c:797 at cqhci_irq+0x254/0x818, CPU#1: kworker/1:0H/24
Modules linked in:
CPU: 1 UID: 0 PID: 24 Comm: kworker/1:0H Not tainted 6.19.0-rc1-00001-g09db0998649d-dirty #204 PREEMPT
Hardware name: Rockchip RK3588 EVB1 V10 Board (DT)
Workqueue: kblockd blk_mq_run_work_fn
pstate: 604000c9 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : cqhci_irq+0x254/0x818
lr : cqhci_irq+0x254/0x818
...
Caido is a web security auditing toolkit. Prior to 0.55.0, Caido blocks non whitelisted domains to reach out through the 8080 port, and shows Host/IP is not allowed to connect to Caido on all endpoints. But this is bypassable by injecting a X-Forwarded-Host: 127.0.0.1:8080 header. This vulnerability is fixed in 0.55.0.