Security Vulnerabilities
- CVEs Published In April 2024
In the Linux kernel, the following vulnerability has been resolved:
thermal: Fix NULL pointer dereferences in of_thermal_ functions
of_parse_thermal_zones() parses the thermal-zones node and registers a
thermal_zone device for each subnode. However, if a thermal zone is
consuming a thermal sensor and that thermal sensor device hasn't probed
yet, an attempt to set trip_point_*_temp for that thermal zone device
can cause a NULL pointer dereference. Fix it.
console:/sys/class/thermal/thermal_zone87 # echo 120000 > trip_point_0_temp
...
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
...
Call trace:
of_thermal_set_trip_temp+0x40/0xc4
trip_point_temp_store+0xc0/0x1dc
dev_attr_store+0x38/0x88
sysfs_kf_write+0x64/0xc0
kernfs_fop_write_iter+0x108/0x1d0
vfs_write+0x2f4/0x368
ksys_write+0x7c/0xec
__arm64_sys_write+0x20/0x30
el0_svc_common.llvm.7279915941325364641+0xbc/0x1bc
do_el0_svc+0x28/0xa0
el0_svc+0x14/0x24
el0_sync_handler+0x88/0xec
el0_sync+0x1c0/0x200
While at it, fix the possible NULL pointer dereference in other
functions as well: of_thermal_get_temp(), of_thermal_set_emul_temp(),
of_thermal_get_trend().
In the Linux kernel, the following vulnerability has been resolved:
scsi: lpfc: Fix list_add() corruption in lpfc_drain_txq()
When parsing the txq list in lpfc_drain_txq(), the driver attempts to pass
the requests to the adapter. If such an attempt fails, a local "fail_msg"
string is set and a log message output. The job is then added to a
completions list for cancellation.
Processing of any further jobs from the txq list continues, but since
"fail_msg" remains set, jobs are added to the completions list regardless
of whether a wqe was passed to the adapter. If successfully added to
txcmplq, jobs are added to both lists resulting in list corruption.
Fix by clearing the fail_msg string after adding a job to the completions
list. This stops the subsequent jobs from being added to the completions
list unless they had an appropriate failure.
In the Linux kernel, the following vulnerability has been resolved:
net: dpaa2-eth: fix use-after-free in dpaa2_eth_remove
Access to netdev after free_netdev() will cause use-after-free bug.
Move debug log before free_netdev() call to avoid it.
In the Linux kernel, the following vulnerability has been resolved:
clk: sunxi-ng: Unregister clocks/resets when unbinding
Currently, unbinding a CCU driver unmaps the device's MMIO region, while
leaving its clocks/resets and their providers registered. This can cause
a page fault later when some clock operation tries to perform MMIO. Fix
this by separating the CCU initialization from the memory allocation,
and then using a devres callback to unregister the clocks and resets.
This also fixes a memory leak of the `struct ccu_reset`, and uses the
correct owner (the specific platform driver) for the clocks and resets.
Early OF clock providers are never unregistered, and limited error
handling is possible, so they are mostly unchanged. The error reporting
is made more consistent by moving the message inside of_sunxi_ccu_probe.
In the Linux kernel, the following vulnerability has been resolved:
usb: host: ohci-tmio: check return value after calling platform_get_resource()
It will cause null-ptr-deref if platform_get_resource() returns NULL,
we need check the return value.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: gus: fix null pointer dereference on pointer block
The pointer block return from snd_gf1_dma_next_block could be
null, so there is a potential null pointer dereference issue.
Fix this by adding a null check before dereference.
In the Linux kernel, the following vulnerability has been resolved:
sched/fair: Prevent dead task groups from regaining cfs_rq's
Kevin is reporting crashes which point to a use-after-free of a cfs_rq
in update_blocked_averages(). Initial debugging revealed that we've
live cfs_rq's (on_list=1) in an about to be kfree()'d task group in
free_fair_sched_group(). However, it was unclear how that can happen.
His kernel config happened to lead to a layout of struct sched_entity
that put the 'my_q' member directly into the middle of the object
which makes it incidentally overlap with SLUB's freelist pointer.
That, in combination with SLAB_FREELIST_HARDENED's freelist pointer
mangling, leads to a reliable access violation in form of a #GP which
made the UAF fail fast.
Michal seems to have run into the same issue[1]. He already correctly
diagnosed that commit a7b359fc6a37 ("sched/fair: Correctly insert
cfs_rq's to list on unthrottle") is causing the preconditions for the
UAF to happen by re-adding cfs_rq's also to task groups that have no
more running tasks, i.e. also to dead ones. His analysis, however,
misses the real root cause and it cannot be seen from the crash
backtrace only, as the real offender is tg_unthrottle_up() getting
called via sched_cfs_period_timer() via the timer interrupt at an
inconvenient time.
When unregister_fair_sched_group() unlinks all cfs_rq's from the dying
task group, it doesn't protect itself from getting interrupted. If the
timer interrupt triggers while we iterate over all CPUs or after
unregister_fair_sched_group() has finished but prior to unlinking the
task group, sched_cfs_period_timer() will execute and walk the list of
task groups, trying to unthrottle cfs_rq's, i.e. re-add them to the
dying task group. These will later -- in free_fair_sched_group() -- be
kfree()'ed while still being linked, leading to the fireworks Kevin
and Michal are seeing.
To fix this race, ensure the dying task group gets unlinked first.
However, simply switching the order of unregistering and unlinking the
task group isn't sufficient, as concurrent RCU walkers might still see
it, as can be seen below:
CPU1: CPU2:
: timer IRQ:
: do_sched_cfs_period_timer():
: :
: distribute_cfs_runtime():
: rcu_read_lock();
: :
: unthrottle_cfs_rq():
sched_offline_group(): :
: walk_tg_tree_from(…,tg_unthrottle_up,…):
list_del_rcu(&tg->list); :
(1) : list_for_each_entry_rcu(child, &parent->children, siblings)
: :
(2) list_del_rcu(&tg->siblings); :
: tg_unthrottle_up():
unregister_fair_sched_group(): struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)];
: :
list_del_leaf_cfs_rq(tg->cfs_rq[cpu]); :
: :
: if (!cfs_rq_is_decayed(cfs_rq) || cfs_rq->nr_running)
(3) : list_add_leaf_cfs_rq(cfs_rq);
: :
: :
: :
: :
:
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
usb: typec: tipd: Remove WARN_ON in tps6598x_block_read
Calling tps6598x_block_read with a higher than allowed len can be
handled by just returning an error. There's no need to crash systems
with panic-on-warn enabled.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: fix null pointer dereference on pointer cs_desc
The pointer cs_desc return from snd_usb_find_clock_source could
be null, so there is a potential null pointer dereference issue.
Fix this by adding a null check before dereference.
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: Update error handler for UCTX and UMEM
In the fast unload flow, the device state is set to internal error,
which indicates that the driver started the destroy process.
In this case, when a destroy command is being executed, it should return
MLX5_CMD_STAT_OK.
Fix MLX5_CMD_OP_DESTROY_UCTX and MLX5_CMD_OP_DESTROY_UMEM to return OK
instead of EIO.
This fixes a call trace in the umem release process -
[ 2633.536695] Call Trace:
[ 2633.537518] ib_uverbs_remove_one+0xc3/0x140 [ib_uverbs]
[ 2633.538596] remove_client_context+0x8b/0xd0 [ib_core]
[ 2633.539641] disable_device+0x8c/0x130 [ib_core]
[ 2633.540615] __ib_unregister_device+0x35/0xa0 [ib_core]
[ 2633.541640] ib_unregister_device+0x21/0x30 [ib_core]
[ 2633.542663] __mlx5_ib_remove+0x38/0x90 [mlx5_ib]
[ 2633.543640] auxiliary_bus_remove+0x1e/0x30 [auxiliary]
[ 2633.544661] device_release_driver_internal+0x103/0x1f0
[ 2633.545679] bus_remove_device+0xf7/0x170
[ 2633.546640] device_del+0x181/0x410
[ 2633.547606] mlx5_rescan_drivers_locked.part.10+0x63/0x160 [mlx5_core]
[ 2633.548777] mlx5_unregister_device+0x27/0x40 [mlx5_core]
[ 2633.549841] mlx5_uninit_one+0x21/0xc0 [mlx5_core]
[ 2633.550864] remove_one+0x69/0xe0 [mlx5_core]
[ 2633.551819] pci_device_remove+0x3b/0xc0
[ 2633.552731] device_release_driver_internal+0x103/0x1f0
[ 2633.553746] unbind_store+0xf6/0x130
[ 2633.554657] kernfs_fop_write+0x116/0x190
[ 2633.555567] vfs_write+0xa5/0x1a0
[ 2633.556407] ksys_write+0x4f/0xb0
[ 2633.557233] do_syscall_64+0x5b/0x1a0
[ 2633.558071] entry_SYSCALL_64_after_hwframe+0x65/0xca
[ 2633.559018] RIP: 0033:0x7f9977132648
[ 2633.559821] Code: 89 02 48 c7 c0 ff ff ff ff eb b3 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 8d 05 55 6f 2d 00 8b 00 85 c0 75 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 41 54 49 89 d4 55
[ 2633.562332] RSP: 002b:00007fffb1a83888 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 2633.563472] RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007f9977132648
[ 2633.564541] RDX: 000000000000000c RSI: 000055b90546e230 RDI: 0000000000000001
[ 2633.565596] RBP: 000055b90546e230 R08: 00007f9977406860 R09: 00007f9977a54740
[ 2633.566653] R10: 0000000000000000 R11: 0000000000000246 R12: 00007f99774056e0
[ 2633.567692] R13: 000000000000000c R14: 00007f9977400880 R15: 000000000000000c
[ 2633.568725] ---[ end trace 10b4fe52945e544d ]---