| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
vt: fix memory overlapping when deleting chars in the buffer
A memory overlapping copy occurs when deleting a long line. This memory
overlapping copy can cause data corruption when scr_memcpyw is optimized
to memcpy because memcpy does not ensure its behavior if the destination
buffer overlaps with the source buffer. The line buffer is not always
broken, because the memcpy utilizes the hardware acceleration, whose
result is not deterministic.
Fix this problem by using replacing the scr_memcpyw with scr_memmovew. |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_taprio: fix possible use-after-free
syzbot reported a nasty crash [1] in net_tx_action() which
made little sense until we got a repro.
This repro installs a taprio qdisc, but providing an
invalid TCA_RATE attribute.
qdisc_create() has to destroy the just initialized
taprio qdisc, and taprio_destroy() is called.
However, the hrtimer used by taprio had already fired,
therefore advance_sched() called __netif_schedule().
Then net_tx_action was trying to use a destroyed qdisc.
We can not undo the __netif_schedule(), so we must wait
until one cpu serviced the qdisc before we can proceed.
Many thanks to Alexander Potapenko for his help.
[1]
BUG: KMSAN: uninit-value in queued_spin_trylock include/asm-generic/qspinlock.h:94 [inline]
BUG: KMSAN: uninit-value in do_raw_spin_trylock include/linux/spinlock.h:191 [inline]
BUG: KMSAN: uninit-value in __raw_spin_trylock include/linux/spinlock_api_smp.h:89 [inline]
BUG: KMSAN: uninit-value in _raw_spin_trylock+0x92/0xa0 kernel/locking/spinlock.c:138
queued_spin_trylock include/asm-generic/qspinlock.h:94 [inline]
do_raw_spin_trylock include/linux/spinlock.h:191 [inline]
__raw_spin_trylock include/linux/spinlock_api_smp.h:89 [inline]
_raw_spin_trylock+0x92/0xa0 kernel/locking/spinlock.c:138
spin_trylock include/linux/spinlock.h:359 [inline]
qdisc_run_begin include/net/sch_generic.h:187 [inline]
qdisc_run+0xee/0x540 include/net/pkt_sched.h:125
net_tx_action+0x77c/0x9a0 net/core/dev.c:5086
__do_softirq+0x1cc/0x7fb kernel/softirq.c:571
run_ksoftirqd+0x2c/0x50 kernel/softirq.c:934
smpboot_thread_fn+0x554/0x9f0 kernel/smpboot.c:164
kthread+0x31b/0x430 kernel/kthread.c:376
ret_from_fork+0x1f/0x30
Uninit was created at:
slab_post_alloc_hook mm/slab.h:732 [inline]
slab_alloc_node mm/slub.c:3258 [inline]
__kmalloc_node_track_caller+0x814/0x1250 mm/slub.c:4970
kmalloc_reserve net/core/skbuff.c:358 [inline]
__alloc_skb+0x346/0xcf0 net/core/skbuff.c:430
alloc_skb include/linux/skbuff.h:1257 [inline]
nlmsg_new include/net/netlink.h:953 [inline]
netlink_ack+0x5f3/0x12b0 net/netlink/af_netlink.c:2436
netlink_rcv_skb+0x55d/0x6c0 net/netlink/af_netlink.c:2507
rtnetlink_rcv+0x30/0x40 net/core/rtnetlink.c:6108
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0xf3b/0x1270 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x1288/0x1440 net/netlink/af_netlink.c:1921
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg net/socket.c:734 [inline]
____sys_sendmsg+0xabc/0xe90 net/socket.c:2482
___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2536
__sys_sendmsg net/socket.c:2565 [inline]
__do_sys_sendmsg net/socket.c:2574 [inline]
__se_sys_sendmsg net/socket.c:2572 [inline]
__x64_sys_sendmsg+0x367/0x540 net/socket.c:2572
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
CPU: 0 PID: 13 Comm: ksoftirqd/0 Not tainted 6.0.0-rc2-syzkaller-47461-gac3859c02d7f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 |
| In the Linux kernel, the following vulnerability has been resolved:
vc_screen: move load of struct vc_data pointer in vcs_read() to avoid UAF
After a call to console_unlock() in vcs_read() the vc_data struct can be
freed by vc_deallocate(). Because of that, the struct vc_data pointer
load must be done at the top of while loop in vcs_read() to avoid a UAF
when vcs_size() is called.
Syzkaller reported a UAF in vcs_size().
BUG: KASAN: use-after-free in vcs_size (drivers/tty/vt/vc_screen.c:215)
Read of size 4 at addr ffff8881137479a8 by task 4a005ed81e27e65/1537
CPU: 0 PID: 1537 Comm: 4a005ed81e27e65 Not tainted 6.2.0-rc5 #1
Hardware name: Red Hat KVM, BIOS 1.15.0-2.module
Call Trace:
<TASK>
__asan_report_load4_noabort (mm/kasan/report_generic.c:350)
vcs_size (drivers/tty/vt/vc_screen.c:215)
vcs_read (drivers/tty/vt/vc_screen.c:415)
vfs_read (fs/read_write.c:468 fs/read_write.c:450)
...
</TASK>
Allocated by task 1191:
...
kmalloc_trace (mm/slab_common.c:1069)
vc_allocate (./include/linux/slab.h:580 ./include/linux/slab.h:720
drivers/tty/vt/vt.c:1128 drivers/tty/vt/vt.c:1108)
con_install (drivers/tty/vt/vt.c:3383)
tty_init_dev (drivers/tty/tty_io.c:1301 drivers/tty/tty_io.c:1413
drivers/tty/tty_io.c:1390)
tty_open (drivers/tty/tty_io.c:2080 drivers/tty/tty_io.c:2126)
chrdev_open (fs/char_dev.c:415)
do_dentry_open (fs/open.c:883)
vfs_open (fs/open.c:1014)
...
Freed by task 1548:
...
kfree (mm/slab_common.c:1021)
vc_port_destruct (drivers/tty/vt/vt.c:1094)
tty_port_destructor (drivers/tty/tty_port.c:296)
tty_port_put (drivers/tty/tty_port.c:312)
vt_disallocate_all (drivers/tty/vt/vt_ioctl.c:662 (discriminator 2))
vt_ioctl (drivers/tty/vt/vt_ioctl.c:903)
tty_ioctl (drivers/tty/tty_io.c:2776)
...
The buggy address belongs to the object at ffff888113747800
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 424 bytes inside of
1024-byte region [ffff888113747800, ffff888113747c00)
The buggy address belongs to the physical page:
page:00000000b3fe6c7c refcount:1 mapcount:0 mapping:0000000000000000
index:0x0 pfn:0x113740
head:00000000b3fe6c7c order:3 compound_mapcount:0 subpages_mapcount:0
compound_pincount:0
anon flags: 0x17ffffc0010200(slab|head|node=0|zone=2|lastcpupid=0x1fffff)
raw: 0017ffffc0010200 ffff888100042dc0 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888113747880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888113747900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff888113747980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888113747a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888113747a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
Disabling lock debugging due to kernel taint |
| In the Linux kernel, the following vulnerability has been resolved:
drm/i915: Avoid potential vm use-after-free
Adding the vm to the vm_xa table makes it visible to userspace, which
could try to race with us to close the vm. So we need to take our extra
reference before putting it in the table.
(cherry picked from commit 99343c46d4e2b34c285d3d5f68ff04274c2f9fb4) |
| In the Linux kernel, the following vulnerability has been resolved:
octeontx2-pf: Fix resource leakage in VF driver unbind
resources allocated like mcam entries to support the Ntuple feature
and hash tables for the tc feature are not getting freed in driver
unbind. This patch fixes the issue. |
| In the Linux kernel, the following vulnerability has been resolved:
nommu: fix memory leak in do_mmap() error path
The preallocation of the maple tree nodes may leak if the error path to
"error_just_free" is taken. Fix this by moving the freeing of the maple
tree nodes to a shared location for all error paths. |
| In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: Fix UAF in svc_tcp_listen_data_ready()
After the listener svc_sock is freed, and before invoking svc_tcp_accept()
for the established child sock, there is a window that the newsock
retaining a freed listener svc_sock in sk_user_data which cloning from
parent. In the race window, if data is received on the newsock, we will
observe use-after-free report in svc_tcp_listen_data_ready().
Reproduce by two tasks:
1. while :; do rpc.nfsd 0 ; rpc.nfsd; done
2. while :; do echo "" | ncat -4 127.0.0.1 2049 ; done
KASAN report:
==================================================================
BUG: KASAN: slab-use-after-free in svc_tcp_listen_data_ready+0x1cf/0x1f0 [sunrpc]
Read of size 8 at addr ffff888139d96228 by task nc/102553
CPU: 7 PID: 102553 Comm: nc Not tainted 6.3.0+ #18
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020
Call Trace:
<IRQ>
dump_stack_lvl+0x33/0x50
print_address_description.constprop.0+0x27/0x310
print_report+0x3e/0x70
kasan_report+0xae/0xe0
svc_tcp_listen_data_ready+0x1cf/0x1f0 [sunrpc]
tcp_data_queue+0x9f4/0x20e0
tcp_rcv_established+0x666/0x1f60
tcp_v4_do_rcv+0x51c/0x850
tcp_v4_rcv+0x23fc/0x2e80
ip_protocol_deliver_rcu+0x62/0x300
ip_local_deliver_finish+0x267/0x350
ip_local_deliver+0x18b/0x2d0
ip_rcv+0x2fb/0x370
__netif_receive_skb_one_core+0x166/0x1b0
process_backlog+0x24c/0x5e0
__napi_poll+0xa2/0x500
net_rx_action+0x854/0xc90
__do_softirq+0x1bb/0x5de
do_softirq+0xcb/0x100
</IRQ>
<TASK>
...
</TASK>
Allocated by task 102371:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
__kasan_kmalloc+0x7b/0x90
svc_setup_socket+0x52/0x4f0 [sunrpc]
svc_addsock+0x20d/0x400 [sunrpc]
__write_ports_addfd+0x209/0x390 [nfsd]
write_ports+0x239/0x2c0 [nfsd]
nfsctl_transaction_write+0xac/0x110 [nfsd]
vfs_write+0x1c3/0xae0
ksys_write+0xed/0x1c0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
Freed by task 102551:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
kasan_save_free_info+0x2a/0x50
__kasan_slab_free+0x106/0x190
__kmem_cache_free+0x133/0x270
svc_xprt_free+0x1e2/0x350 [sunrpc]
svc_xprt_destroy_all+0x25a/0x440 [sunrpc]
nfsd_put+0x125/0x240 [nfsd]
nfsd_svc+0x2cb/0x3c0 [nfsd]
write_threads+0x1ac/0x2a0 [nfsd]
nfsctl_transaction_write+0xac/0x110 [nfsd]
vfs_write+0x1c3/0xae0
ksys_write+0xed/0x1c0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
Fix the UAF by simply doing nothing in svc_tcp_listen_data_ready()
if state != TCP_LISTEN, that will avoid dereferencing svsk for all
child socket. |
| In the Linux kernel, the following vulnerability has been resolved:
Input: cyapa - add missing input core locking to suspend/resume functions
Grab input->mutex during suspend/resume functions like it is done in
other input drivers. This fixes the following warning during system
suspend/resume cycle on Samsung Exynos5250-based Snow Chromebook:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 1680 at drivers/input/input.c:2291 input_device_enabled+0x68/0x6c
Modules linked in: ...
CPU: 1 PID: 1680 Comm: kworker/u4:12 Tainted: G W 6.6.0-rc5-next-20231009 #14109
Hardware name: Samsung Exynos (Flattened Device Tree)
Workqueue: events_unbound async_run_entry_fn
unwind_backtrace from show_stack+0x10/0x14
show_stack from dump_stack_lvl+0x58/0x70
dump_stack_lvl from __warn+0x1a8/0x1cc
__warn from warn_slowpath_fmt+0x18c/0x1b4
warn_slowpath_fmt from input_device_enabled+0x68/0x6c
input_device_enabled from cyapa_gen3_set_power_mode+0x13c/0x1dc
cyapa_gen3_set_power_mode from cyapa_reinitialize+0x10c/0x15c
cyapa_reinitialize from cyapa_resume+0x48/0x98
cyapa_resume from dpm_run_callback+0x90/0x298
dpm_run_callback from device_resume+0xb4/0x258
device_resume from async_resume+0x20/0x64
async_resume from async_run_entry_fn+0x40/0x15c
async_run_entry_fn from process_scheduled_works+0xbc/0x6a8
process_scheduled_works from worker_thread+0x188/0x454
worker_thread from kthread+0x108/0x140
kthread from ret_from_fork+0x14/0x28
Exception stack(0xf1625fb0 to 0xf1625ff8)
...
---[ end trace 0000000000000000 ]---
...
------------[ cut here ]------------
WARNING: CPU: 1 PID: 1680 at drivers/input/input.c:2291 input_device_enabled+0x68/0x6c
Modules linked in: ...
CPU: 1 PID: 1680 Comm: kworker/u4:12 Tainted: G W 6.6.0-rc5-next-20231009 #14109
Hardware name: Samsung Exynos (Flattened Device Tree)
Workqueue: events_unbound async_run_entry_fn
unwind_backtrace from show_stack+0x10/0x14
show_stack from dump_stack_lvl+0x58/0x70
dump_stack_lvl from __warn+0x1a8/0x1cc
__warn from warn_slowpath_fmt+0x18c/0x1b4
warn_slowpath_fmt from input_device_enabled+0x68/0x6c
input_device_enabled from cyapa_gen3_set_power_mode+0x13c/0x1dc
cyapa_gen3_set_power_mode from cyapa_reinitialize+0x10c/0x15c
cyapa_reinitialize from cyapa_resume+0x48/0x98
cyapa_resume from dpm_run_callback+0x90/0x298
dpm_run_callback from device_resume+0xb4/0x258
device_resume from async_resume+0x20/0x64
async_resume from async_run_entry_fn+0x40/0x15c
async_run_entry_fn from process_scheduled_works+0xbc/0x6a8
process_scheduled_works from worker_thread+0x188/0x454
worker_thread from kthread+0x108/0x140
kthread from ret_from_fork+0x14/0x28
Exception stack(0xf1625fb0 to 0xf1625ff8)
...
---[ end trace 0000000000000000 ]--- |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: Fix possible null pointer dereference
abo->tbo.resource may be NULL in amdgpu_vm_bo_update. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: typec: tcpm: Fix NULL pointer dereference in tcpm_pd_svdm()
It is possible that typec_register_partner() returns ERR_PTR on failure.
When port->partner is an error, a NULL pointer dereference may occur as
shown below.
[91222.095236][ T319] typec port0: failed to register partner (-17)
...
[91225.061491][ T319] Unable to handle kernel NULL pointer dereference
at virtual address 000000000000039f
[91225.274642][ T319] pc : tcpm_pd_data_request+0x310/0x13fc
[91225.274646][ T319] lr : tcpm_pd_data_request+0x298/0x13fc
[91225.308067][ T319] Call trace:
[91225.308070][ T319] tcpm_pd_data_request+0x310/0x13fc
[91225.308073][ T319] tcpm_pd_rx_handler+0x100/0x9e8
[91225.355900][ T319] kthread_worker_fn+0x178/0x58c
[91225.355902][ T319] kthread+0x150/0x200
[91225.355905][ T319] ret_from_fork+0x10/0x30
Add a check for port->partner to avoid dereferencing a NULL pointer. |
| In the Linux kernel, the following vulnerability has been resolved:
pstore/platform: Add check for kstrdup
Add check for the return value of kstrdup() and return the error
if it fails in order to avoid NULL pointer dereference. |
| In the Linux kernel, the following vulnerability has been resolved:
perf: hisi: Fix use-after-free when register pmu fails
When we fail to register the uncore pmu, the pmu context may not been
allocated. The error handing will call cpuhp_state_remove_instance()
to call uncore pmu offline callback, which migrate the pmu context.
Since that's liable to lead to some kind of use-after-free.
Use cpuhp_state_remove_instance_nocalls() instead of
cpuhp_state_remove_instance() so that the notifiers don't execute after
the PMU device has been failed to register. |
| In the Linux kernel, the following vulnerability has been resolved:
tipc: Change nla_policy for bearer-related names to NLA_NUL_STRING
syzbot reported the following uninit-value access issue [1]:
=====================================================
BUG: KMSAN: uninit-value in strlen lib/string.c:418 [inline]
BUG: KMSAN: uninit-value in strstr+0xb8/0x2f0 lib/string.c:756
strlen lib/string.c:418 [inline]
strstr+0xb8/0x2f0 lib/string.c:756
tipc_nl_node_reset_link_stats+0x3ea/0xb50 net/tipc/node.c:2595
genl_family_rcv_msg_doit net/netlink/genetlink.c:971 [inline]
genl_family_rcv_msg net/netlink/genetlink.c:1051 [inline]
genl_rcv_msg+0x11ec/0x1290 net/netlink/genetlink.c:1066
netlink_rcv_skb+0x371/0x650 net/netlink/af_netlink.c:2545
genl_rcv+0x40/0x60 net/netlink/genetlink.c:1075
netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
netlink_unicast+0xf47/0x1250 net/netlink/af_netlink.c:1368
netlink_sendmsg+0x1238/0x13d0 net/netlink/af_netlink.c:1910
sock_sendmsg_nosec net/socket.c:730 [inline]
sock_sendmsg net/socket.c:753 [inline]
____sys_sendmsg+0x9c2/0xd60 net/socket.c:2541
___sys_sendmsg+0x28d/0x3c0 net/socket.c:2595
__sys_sendmsg net/socket.c:2624 [inline]
__do_sys_sendmsg net/socket.c:2633 [inline]
__se_sys_sendmsg net/socket.c:2631 [inline]
__x64_sys_sendmsg+0x307/0x490 net/socket.c:2631
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Uninit was created at:
slab_post_alloc_hook+0x12f/0xb70 mm/slab.h:767
slab_alloc_node mm/slub.c:3478 [inline]
kmem_cache_alloc_node+0x577/0xa80 mm/slub.c:3523
kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:559
__alloc_skb+0x318/0x740 net/core/skbuff.c:650
alloc_skb include/linux/skbuff.h:1286 [inline]
netlink_alloc_large_skb net/netlink/af_netlink.c:1214 [inline]
netlink_sendmsg+0xb34/0x13d0 net/netlink/af_netlink.c:1885
sock_sendmsg_nosec net/socket.c:730 [inline]
sock_sendmsg net/socket.c:753 [inline]
____sys_sendmsg+0x9c2/0xd60 net/socket.c:2541
___sys_sendmsg+0x28d/0x3c0 net/socket.c:2595
__sys_sendmsg net/socket.c:2624 [inline]
__do_sys_sendmsg net/socket.c:2633 [inline]
__se_sys_sendmsg net/socket.c:2631 [inline]
__x64_sys_sendmsg+0x307/0x490 net/socket.c:2631
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
TIPC bearer-related names including link names must be null-terminated
strings. If a link name which is not null-terminated is passed through
netlink, strstr() and similar functions can cause buffer overrun. This
causes the above issue.
This patch changes the nla_policy for bearer-related names from NLA_STRING
to NLA_NUL_STRING. This resolves the issue by ensuring that only
null-terminated strings are accepted as bearer-related names.
syzbot reported similar uninit-value issue related to bearer names [2]. The
root cause of this issue is that a non-null-terminated bearer name was
passed. This patch also resolved this issue. |
| In the Linux kernel, the following vulnerability has been resolved:
Input: synaptics-rmi4 - fix use after free in rmi_unregister_function()
The put_device() calls rmi_release_function() which frees "fn" so the
dereference on the next line "fn->num_of_irqs" is a use after free.
Move the put_device() to the end to fix this. |
| In the Linux kernel, the following vulnerability has been resolved:
nbd: fix uaf in nbd_open
Commit 4af5f2e03013 ("nbd: use blk_mq_alloc_disk and
blk_cleanup_disk") cleans up disk by blk_cleanup_disk() and it won't set
disk->private_data as NULL as before. UAF may be triggered in nbd_open()
if someone tries to open nbd device right after nbd_put() since nbd has
been free in nbd_dev_remove().
Fix this by implementing ->free_disk and free private data in it. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: ath11k: fix htt pktlog locking
The ath11k active pdevs are protected by RCU but the htt pktlog handling
code calling ath11k_mac_get_ar_by_pdev_id() was not marked as a
read-side critical section.
Mark the code in question as an RCU read-side critical section to avoid
any potential use-after-free issues.
Compile tested only. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: ath11k: fix dfs radar event locking
The ath11k active pdevs are protected by RCU but the DFS radar event
handling code calling ath11k_mac_get_ar_by_pdev_id() was not marked as a
read-side critical section.
Mark the code in question as an RCU read-side critical section to avoid
any potential use-after-free issues.
Compile tested only. |
| In the Linux kernel, the following vulnerability has been resolved:
i915/perf: Fix NULL deref bugs with drm_dbg() calls
When i915 perf interface is not available dereferencing it will lead to
NULL dereferences.
As returning -ENOTSUPP is pretty clear return when perf interface is not
available.
[tursulin: added stable tag]
(cherry picked from commit 36f27350ff745bd228ab04d7845dfbffc177a889) |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: ath11k: fix gtk offload status event locking
The ath11k active pdevs are protected by RCU but the gtk offload status
event handling code calling ath11k_mac_get_arvif_by_vdev_id() was not
marked as a read-side critical section.
Mark the code in question as an RCU read-side critical section to avoid
any potential use-after-free issues.
Compile tested only. |
| In the Linux kernel, the following vulnerability has been resolved:
sched/psi: Fix use-after-free in ep_remove_wait_queue()
If a non-root cgroup gets removed when there is a thread that registered
trigger and is polling on a pressure file within the cgroup, the polling
waitqueue gets freed in the following path:
do_rmdir
cgroup_rmdir
kernfs_drain_open_files
cgroup_file_release
cgroup_pressure_release
psi_trigger_destroy
However, the polling thread still has a reference to the pressure file and
will access the freed waitqueue when the file is closed or upon exit:
fput
ep_eventpoll_release
ep_free
ep_remove_wait_queue
remove_wait_queue
This results in use-after-free as pasted below.
The fundamental problem here is that cgroup_file_release() (and
consequently waitqueue's lifetime) is not tied to the file's real lifetime.
Using wake_up_pollfree() here might be less than ideal, but it is in line
with the comment at commit 42288cb44c4b ("wait: add wake_up_pollfree()")
since the waitqueue's lifetime is not tied to file's one and can be
considered as another special case. While this would be fixable by somehow
making cgroup_file_release() be tied to the fput(), it would require
sizable refactoring at cgroups or higher layer which might be more
justifiable if we identify more cases like this.
BUG: KASAN: use-after-free in _raw_spin_lock_irqsave+0x60/0xc0
Write of size 4 at addr ffff88810e625328 by task a.out/4404
CPU: 19 PID: 4404 Comm: a.out Not tainted 6.2.0-rc6 #38
Hardware name: Amazon EC2 c5a.8xlarge/, BIOS 1.0 10/16/2017
Call Trace:
<TASK>
dump_stack_lvl+0x73/0xa0
print_report+0x16c/0x4e0
kasan_report+0xc3/0xf0
kasan_check_range+0x2d2/0x310
_raw_spin_lock_irqsave+0x60/0xc0
remove_wait_queue+0x1a/0xa0
ep_free+0x12c/0x170
ep_eventpoll_release+0x26/0x30
__fput+0x202/0x400
task_work_run+0x11d/0x170
do_exit+0x495/0x1130
do_group_exit+0x100/0x100
get_signal+0xd67/0xde0
arch_do_signal_or_restart+0x2a/0x2b0
exit_to_user_mode_prepare+0x94/0x100
syscall_exit_to_user_mode+0x20/0x40
do_syscall_64+0x52/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
</TASK>
Allocated by task 4404:
kasan_set_track+0x3d/0x60
__kasan_kmalloc+0x85/0x90
psi_trigger_create+0x113/0x3e0
pressure_write+0x146/0x2e0
cgroup_file_write+0x11c/0x250
kernfs_fop_write_iter+0x186/0x220
vfs_write+0x3d8/0x5c0
ksys_write+0x90/0x110
do_syscall_64+0x43/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Freed by task 4407:
kasan_set_track+0x3d/0x60
kasan_save_free_info+0x27/0x40
____kasan_slab_free+0x11d/0x170
slab_free_freelist_hook+0x87/0x150
__kmem_cache_free+0xcb/0x180
psi_trigger_destroy+0x2e8/0x310
cgroup_file_release+0x4f/0xb0
kernfs_drain_open_files+0x165/0x1f0
kernfs_drain+0x162/0x1a0
__kernfs_remove+0x1fb/0x310
kernfs_remove_by_name_ns+0x95/0xe0
cgroup_addrm_files+0x67f/0x700
cgroup_destroy_locked+0x283/0x3c0
cgroup_rmdir+0x29/0x100
kernfs_iop_rmdir+0xd1/0x140
vfs_rmdir+0xfe/0x240
do_rmdir+0x13d/0x280
__x64_sys_rmdir+0x2c/0x30
do_syscall_64+0x43/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd |
