| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
af_unix: fix use-after-free in unix_stream_read_actor()
syzbot reported the following crash [1]
After releasing unix socket lock, u->oob_skb can be changed
by another thread. We must temporarily increase skb refcount
to make sure this other thread will not free the skb under us.
[1]
BUG: KASAN: slab-use-after-free in unix_stream_read_actor+0xa7/0xc0 net/unix/af_unix.c:2866
Read of size 4 at addr ffff88801f3b9cc4 by task syz-executor107/5297
CPU: 1 PID: 5297 Comm: syz-executor107 Not tainted 6.6.0-syzkaller-15910-gb8e3a87a627b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0xc4/0x620 mm/kasan/report.c:475
kasan_report+0xda/0x110 mm/kasan/report.c:588
unix_stream_read_actor+0xa7/0xc0 net/unix/af_unix.c:2866
unix_stream_recv_urg net/unix/af_unix.c:2587 [inline]
unix_stream_read_generic+0x19a5/0x2480 net/unix/af_unix.c:2666
unix_stream_recvmsg+0x189/0x1b0 net/unix/af_unix.c:2903
sock_recvmsg_nosec net/socket.c:1044 [inline]
sock_recvmsg+0xe2/0x170 net/socket.c:1066
____sys_recvmsg+0x21f/0x5c0 net/socket.c:2803
___sys_recvmsg+0x115/0x1a0 net/socket.c:2845
__sys_recvmsg+0x114/0x1e0 net/socket.c:2875
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7fc67492c559
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc6748ab228 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 000000000000001c RCX: 00007fc67492c559
RDX: 0000000040010083 RSI: 0000000020000140 RDI: 0000000000000004
RBP: 00007fc6749b6348 R08: 00007fc6748ab6c0 R09: 00007fc6748ab6c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc6749b6340
R13: 00007fc6749b634c R14: 00007ffe9fac52a0 R15: 00007ffe9fac5388
</TASK>
Allocated by task 5295:
kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
__kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:328
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook mm/slab.h:763 [inline]
slab_alloc_node mm/slub.c:3478 [inline]
kmem_cache_alloc_node+0x180/0x3c0 mm/slub.c:3523
__alloc_skb+0x287/0x330 net/core/skbuff.c:641
alloc_skb include/linux/skbuff.h:1286 [inline]
alloc_skb_with_frags+0xe4/0x710 net/core/skbuff.c:6331
sock_alloc_send_pskb+0x7e4/0x970 net/core/sock.c:2780
sock_alloc_send_skb include/net/sock.h:1884 [inline]
queue_oob net/unix/af_unix.c:2147 [inline]
unix_stream_sendmsg+0xb5f/0x10a0 net/unix/af_unix.c:2301
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0xd5/0x180 net/socket.c:745
____sys_sendmsg+0x6ac/0x940 net/socket.c:2584
___sys_sendmsg+0x135/0x1d0 net/socket.c:2638
__sys_sendmsg+0x117/0x1e0 net/socket.c:2667
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b
Freed by task 5295:
kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522
____kasan_slab_free mm/kasan/common.c:236 [inline]
____kasan_slab_free+0x15b/0x1b0 mm/kasan/common.c:200
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1800 [inline]
slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826
slab_free mm/slub.c:3809 [inline]
kmem_cache_free+0xf8/0x340 mm/slub.c:3831
kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:1015
__kfree_skb net/core/skbuff.c:1073 [inline]
consume_skb net/core/skbuff.c:1288 [inline]
consume_skb+0xdf/0x170 net/core/skbuff.c:1282
queue_oob net/unix/af_unix.c:2178 [inline]
u
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: ath12k: fix htt mlo-offset event locking
The ath12k active pdevs are protected by RCU but the htt mlo-offset
event handling code calling ath12k_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:
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 |
| In the Linux kernel, the following vulnerability has been resolved:
can: j1939: Fix UAF in j1939_sk_match_filter during setsockopt(SO_J1939_FILTER)
Lock jsk->sk to prevent UAF when setsockopt(..., SO_J1939_FILTER, ...)
modifies jsk->filters while receiving packets.
Following trace was seen on affected system:
==================================================================
BUG: KASAN: slab-use-after-free in j1939_sk_recv_match_one+0x1af/0x2d0 [can_j1939]
Read of size 4 at addr ffff888012144014 by task j1939/350
CPU: 0 PID: 350 Comm: j1939 Tainted: G W OE 6.5.0-rc5 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
print_report+0xd3/0x620
? kasan_complete_mode_report_info+0x7d/0x200
? j1939_sk_recv_match_one+0x1af/0x2d0 [can_j1939]
kasan_report+0xc2/0x100
? j1939_sk_recv_match_one+0x1af/0x2d0 [can_j1939]
__asan_load4+0x84/0xb0
j1939_sk_recv_match_one+0x1af/0x2d0 [can_j1939]
j1939_sk_recv+0x20b/0x320 [can_j1939]
? __kasan_check_write+0x18/0x20
? __pfx_j1939_sk_recv+0x10/0x10 [can_j1939]
? j1939_simple_recv+0x69/0x280 [can_j1939]
? j1939_ac_recv+0x5e/0x310 [can_j1939]
j1939_can_recv+0x43f/0x580 [can_j1939]
? __pfx_j1939_can_recv+0x10/0x10 [can_j1939]
? raw_rcv+0x42/0x3c0 [can_raw]
? __pfx_j1939_can_recv+0x10/0x10 [can_j1939]
can_rcv_filter+0x11f/0x350 [can]
can_receive+0x12f/0x190 [can]
? __pfx_can_rcv+0x10/0x10 [can]
can_rcv+0xdd/0x130 [can]
? __pfx_can_rcv+0x10/0x10 [can]
__netif_receive_skb_one_core+0x13d/0x150
? __pfx___netif_receive_skb_one_core+0x10/0x10
? __kasan_check_write+0x18/0x20
? _raw_spin_lock_irq+0x8c/0xe0
__netif_receive_skb+0x23/0xb0
process_backlog+0x107/0x260
__napi_poll+0x69/0x310
net_rx_action+0x2a1/0x580
? __pfx_net_rx_action+0x10/0x10
? __pfx__raw_spin_lock+0x10/0x10
? handle_irq_event+0x7d/0xa0
__do_softirq+0xf3/0x3f8
do_softirq+0x53/0x80
</IRQ>
<TASK>
__local_bh_enable_ip+0x6e/0x70
netif_rx+0x16b/0x180
can_send+0x32b/0x520 [can]
? __pfx_can_send+0x10/0x10 [can]
? __check_object_size+0x299/0x410
raw_sendmsg+0x572/0x6d0 [can_raw]
? __pfx_raw_sendmsg+0x10/0x10 [can_raw]
? apparmor_socket_sendmsg+0x2f/0x40
? __pfx_raw_sendmsg+0x10/0x10 [can_raw]
sock_sendmsg+0xef/0x100
sock_write_iter+0x162/0x220
? __pfx_sock_write_iter+0x10/0x10
? __rtnl_unlock+0x47/0x80
? security_file_permission+0x54/0x320
vfs_write+0x6ba/0x750
? __pfx_vfs_write+0x10/0x10
? __fget_light+0x1ca/0x1f0
? __rcu_read_unlock+0x5b/0x280
ksys_write+0x143/0x170
? __pfx_ksys_write+0x10/0x10
? __kasan_check_read+0x15/0x20
? fpregs_assert_state_consistent+0x62/0x70
__x64_sys_write+0x47/0x60
do_syscall_64+0x60/0x90
? do_syscall_64+0x6d/0x90
? irqentry_exit+0x3f/0x50
? exc_page_fault+0x79/0xf0
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
Allocated by task 348:
kasan_save_stack+0x2a/0x50
kasan_set_track+0x29/0x40
kasan_save_alloc_info+0x1f/0x30
__kasan_kmalloc+0xb5/0xc0
__kmalloc_node_track_caller+0x67/0x160
j1939_sk_setsockopt+0x284/0x450 [can_j1939]
__sys_setsockopt+0x15c/0x2f0
__x64_sys_setsockopt+0x6b/0x80
do_syscall_64+0x60/0x90
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
Freed by task 349:
kasan_save_stack+0x2a/0x50
kasan_set_track+0x29/0x40
kasan_save_free_info+0x2f/0x50
__kasan_slab_free+0x12e/0x1c0
__kmem_cache_free+0x1b9/0x380
kfree+0x7a/0x120
j1939_sk_setsockopt+0x3b2/0x450 [can_j1939]
__sys_setsockopt+0x15c/0x2f0
__x64_sys_setsockopt+0x6b/0x80
do_syscall_64+0x60/0x90
entry_SYSCALL_64_after_hwframe+0x6e/0xd8 |
| In the Linux kernel, the following vulnerability has been resolved:
sh: push-switch: Reorder cleanup operations to avoid use-after-free bug
The original code puts flush_work() before timer_shutdown_sync()
in switch_drv_remove(). Although we use flush_work() to stop
the worker, it could be rescheduled in switch_timer(). As a result,
a use-after-free bug can occur. The details are shown below:
(cpu 0) | (cpu 1)
switch_drv_remove() |
flush_work() |
... | switch_timer // timer
| schedule_work(&psw->work)
timer_shutdown_sync() |
... | switch_work_handler // worker
kfree(psw) // free |
| psw->state = 0 // use
This patch puts timer_shutdown_sync() before flush_work() to
mitigate the bugs. As a result, the worker and timer will be
stopped safely before the deallocate operations. |
| In the Linux kernel, the following vulnerability has been resolved:
x86/mm, kexec, ima: Use memblock_free_late() from ima_free_kexec_buffer()
The code calling ima_free_kexec_buffer() runs long after the memblock
allocator has already been torn down, potentially resulting in a use
after free in memblock_isolate_range().
With KASAN or KFENCE, this use after free will result in a BUG
from the idle task, and a subsequent kernel panic.
Switch ima_free_kexec_buffer() over to memblock_free_late() to avoid
that bug. |
| In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix potential use after free in nilfs_gccache_submit_read_data()
In nilfs_gccache_submit_read_data(), brelse(bh) is called to drop the
reference count of bh when the call to nilfs_dat_translate() fails. If
the reference count hits 0 and its owner page gets unlocked, bh may be
freed. However, bh->b_page is dereferenced to put the page after that,
which may result in a use-after-free bug. This patch moves the release
operation after unlocking and putting the page.
NOTE: The function in question is only called in GC, and in combination
with current userland tools, address translation using DAT does not occur
in that function, so the code path that causes this issue will not be
executed. However, it is possible to run that code path by intentionally
modifying the userland GC library or by calling the GC ioctl directly.
[konishi.ryusuke@gmail.com: NOTE added to the commit log] |
| In the Linux kernel, the following vulnerability has been resolved:
ieee802154: ca8210: Fix a potential UAF in ca8210_probe
If of_clk_add_provider() fails in ca8210_register_ext_clock(),
it calls clk_unregister() to release priv->clk and returns an
error. However, the caller ca8210_probe() then calls ca8210_remove(),
where priv->clk is freed again in ca8210_unregister_ext_clock(). In
this case, a use-after-free may happen in the second time we call
clk_unregister().
Fix this by removing the first clk_unregister(). Also, priv->clk could
be an error code on failure of clk_register_fixed_rate(). Use
IS_ERR_OR_NULL to catch this case in ca8210_unregister_ext_clock(). |
| In the Linux kernel, the following vulnerability has been resolved:
ravb: Fix use-after-free issue in ravb_tx_timeout_work()
The ravb_stop() should call cancel_work_sync(). Otherwise,
ravb_tx_timeout_work() is possible to use the freed priv after
ravb_remove() was called like below:
CPU0 CPU1
ravb_tx_timeout()
ravb_remove()
unregister_netdev()
free_netdev(ndev)
// free priv
ravb_tx_timeout_work()
// use priv
unregister_netdev() will call .ndo_stop() so that ravb_stop() is
called. And, after phy_stop() is called, netif_carrier_off()
is also called. So that .ndo_tx_timeout() will not be called
after phy_stop(). |
| In the Linux kernel, the following vulnerability has been resolved:
tee: amdtee: fix use-after-free vulnerability in amdtee_close_session
There is a potential race condition in amdtee_close_session that may
cause use-after-free in amdtee_open_session. For instance, if a session
has refcount == 1, and one thread tries to free this session via:
kref_put(&sess->refcount, destroy_session);
the reference count will get decremented, and the next step would be to
call destroy_session(). However, if in another thread,
amdtee_open_session() is called before destroy_session() has completed
execution, alloc_session() may return 'sess' that will be freed up
later in destroy_session() leading to use-after-free in
amdtee_open_session.
To fix this issue, treat decrement of sess->refcount and removal of
'sess' from session list in destroy_session() as a critical section, so
that it is executed atomically. |
| In the Linux kernel, the following vulnerability has been resolved:
net: nfc: fix races in nfc_llcp_sock_get() and nfc_llcp_sock_get_sn()
Sili Luo reported a race in nfc_llcp_sock_get(), leading to UAF.
Getting a reference on the socket found in a lookup while
holding a lock should happen before releasing the lock.
nfc_llcp_sock_get_sn() has a similar problem.
Finally nfc_llcp_recv_snl() needs to make sure the socket
found by nfc_llcp_sock_from_sn() does not disappear. |
| In the Linux kernel, the following vulnerability has been resolved:
media: mtk-jpeg: Fix use after free bug due to error path handling in mtk_jpeg_dec_device_run
In mtk_jpeg_probe, &jpeg->job_timeout_work is bound with
mtk_jpeg_job_timeout_work.
In mtk_jpeg_dec_device_run, if error happens in
mtk_jpeg_set_dec_dst, it will finally start the worker while
mark the job as finished by invoking v4l2_m2m_job_finish.
There are two methods to trigger the bug. If we remove the
module, it which will call mtk_jpeg_remove to make cleanup.
The possible sequence is as follows, which will cause a
use-after-free bug.
CPU0 CPU1
mtk_jpeg_dec_... |
start worker |
|mtk_jpeg_job_timeout_work
mtk_jpeg_remove |
v4l2_m2m_release |
kfree(m2m_dev); |
|
| v4l2_m2m_get_curr_priv
| m2m_dev->curr_ctx //use
If we close the file descriptor, which will call mtk_jpeg_release,
it will have a similar sequence.
Fix this bug by starting timeout worker only if started jpegdec worker
successfully. Then v4l2_m2m_job_finish will only be called in
either mtk_jpeg_job_timeout_work or mtk_jpeg_dec_device_run. |
| In the Linux kernel, the following vulnerability has been resolved:
mctp: perform route lookups under a RCU read-side lock
Our current route lookups (mctp_route_lookup and mctp_route_lookup_null)
traverse the net's route list without the RCU read lock held. This means
the route lookup is subject to preemption, resulting in an potential
grace period expiry, and so an eventual kfree() while we still have the
route pointer.
Add the proper read-side critical section locks around the route
lookups, preventing premption and a possible parallel kfree.
The remaining net->mctp.routes accesses are already under a
rcu_read_lock, or protected by the RTNL for updates.
Based on an analysis from Sili Luo <rootlab@huawei.com>, where
introducing a delay in the route lookup could cause a UAF on
simultaneous sendmsg() and route deletion. |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix uaf in smb20_oplock_break_ack
drop reference after use opinfo. |
| In the Linux kernel, the following vulnerability has been resolved:
drivers/amd/pm: fix a use-after-free in kv_parse_power_table
When ps allocated by kzalloc equals to NULL, kv_parse_power_table
frees adev->pm.dpm.ps that allocated before. However, after the control
flow goes through the following call chains:
kv_parse_power_table
|-> kv_dpm_init
|-> kv_dpm_sw_init
|-> kv_dpm_fini
The adev->pm.dpm.ps is used in the for loop of kv_dpm_fini after its
first free in kv_parse_power_table and causes a use-after-free bug. |
| In the Linux kernel, the following vulnerability has been resolved:
class: fix use-after-free in class_register()
The lock_class_key is still registered and can be found in
lock_keys_hash hlist after subsys_private is freed in error
handler path.A task who iterate over the lock_keys_hash
later may cause use-after-free.So fix that up and unregister
the lock_class_key before kfree(cp).
On our platform, a driver fails to kset_register because of
creating duplicate filename '/class/xxx'.With Kasan enabled,
it prints a invalid-access bug report.
KASAN bug report:
BUG: KASAN: invalid-access in lockdep_register_key+0x19c/0x1bc
Write of size 8 at addr 15ffff808b8c0368 by task modprobe/252
Pointer tag: [15], memory tag: [fe]
CPU: 7 PID: 252 Comm: modprobe Tainted: G W
6.6.0-mainline-maybe-dirty #1
Call trace:
dump_backtrace+0x1b0/0x1e4
show_stack+0x2c/0x40
dump_stack_lvl+0xac/0xe0
print_report+0x18c/0x4d8
kasan_report+0xe8/0x148
__hwasan_store8_noabort+0x88/0x98
lockdep_register_key+0x19c/0x1bc
class_register+0x94/0x1ec
init_module+0xbc/0xf48 [rfkill]
do_one_initcall+0x17c/0x72c
do_init_module+0x19c/0x3f8
...
Memory state around the buggy address:
ffffff808b8c0100: 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a
ffffff808b8c0200: 8a 8a 8a 8a 8a 8a 8a 8a fe fe fe fe fe fe fe fe
>ffffff808b8c0300: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
^
ffffff808b8c0400: 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03
As CONFIG_KASAN_GENERIC is not set, Kasan reports invalid-access
not use-after-free here.In this case, modprobe is manipulating
the corrupted lock_keys_hash hlish where lock_class_key is already
freed before.
It's worth noting that this only can happen if lockdep is enabled,
which is not true for normal system. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Defer the free of inner map when necessary
When updating or deleting an inner map in map array or map htab, the map
may still be accessed by non-sleepable program or sleepable program.
However bpf_map_fd_put_ptr() decreases the ref-counter of the inner map
directly through bpf_map_put(), if the ref-counter is the last one
(which is true for most cases), the inner map will be freed by
ops->map_free() in a kworker. But for now, most .map_free() callbacks
don't use synchronize_rcu() or its variants to wait for the elapse of a
RCU grace period, so after the invocation of ops->map_free completes,
the bpf program which is accessing the inner map may incur
use-after-free problem.
Fix the free of inner map by invoking bpf_map_free_deferred() after both
one RCU grace period and one tasks trace RCU grace period if the inner
map has been removed from the outer map before. The deferment is
accomplished by using call_rcu() or call_rcu_tasks_trace() when
releasing the last ref-counter of bpf map. The newly-added rcu_head
field in bpf_map shares the same storage space with work field to
reduce the size of bpf_map. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix a race condition between btf_put() and map_free()
When running `./test_progs -j` in my local vm with latest kernel,
I once hit a kasan error like below:
[ 1887.184724] BUG: KASAN: slab-use-after-free in bpf_rb_root_free+0x1f8/0x2b0
[ 1887.185599] Read of size 4 at addr ffff888106806910 by task kworker/u12:2/2830
[ 1887.186498]
[ 1887.186712] CPU: 3 PID: 2830 Comm: kworker/u12:2 Tainted: G OEL 6.7.0-rc3-00699-g90679706d486-dirty #494
[ 1887.188034] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[ 1887.189618] Workqueue: events_unbound bpf_map_free_deferred
[ 1887.190341] Call Trace:
[ 1887.190666] <TASK>
[ 1887.190949] dump_stack_lvl+0xac/0xe0
[ 1887.191423] ? nf_tcp_handle_invalid+0x1b0/0x1b0
[ 1887.192019] ? panic+0x3c0/0x3c0
[ 1887.192449] print_report+0x14f/0x720
[ 1887.192930] ? preempt_count_sub+0x1c/0xd0
[ 1887.193459] ? __virt_addr_valid+0xac/0x120
[ 1887.194004] ? bpf_rb_root_free+0x1f8/0x2b0
[ 1887.194572] kasan_report+0xc3/0x100
[ 1887.195085] ? bpf_rb_root_free+0x1f8/0x2b0
[ 1887.195668] bpf_rb_root_free+0x1f8/0x2b0
[ 1887.196183] ? __bpf_obj_drop_impl+0xb0/0xb0
[ 1887.196736] ? preempt_count_sub+0x1c/0xd0
[ 1887.197270] ? preempt_count_sub+0x1c/0xd0
[ 1887.197802] ? _raw_spin_unlock+0x1f/0x40
[ 1887.198319] bpf_obj_free_fields+0x1d4/0x260
[ 1887.198883] array_map_free+0x1a3/0x260
[ 1887.199380] bpf_map_free_deferred+0x7b/0xe0
[ 1887.199943] process_scheduled_works+0x3a2/0x6c0
[ 1887.200549] worker_thread+0x633/0x890
[ 1887.201047] ? __kthread_parkme+0xd7/0xf0
[ 1887.201574] ? kthread+0x102/0x1d0
[ 1887.202020] kthread+0x1ab/0x1d0
[ 1887.202447] ? pr_cont_work+0x270/0x270
[ 1887.202954] ? kthread_blkcg+0x50/0x50
[ 1887.203444] ret_from_fork+0x34/0x50
[ 1887.203914] ? kthread_blkcg+0x50/0x50
[ 1887.204397] ret_from_fork_asm+0x11/0x20
[ 1887.204913] </TASK>
[ 1887.204913] </TASK>
[ 1887.205209]
[ 1887.205416] Allocated by task 2197:
[ 1887.205881] kasan_set_track+0x3f/0x60
[ 1887.206366] __kasan_kmalloc+0x6e/0x80
[ 1887.206856] __kmalloc+0xac/0x1a0
[ 1887.207293] btf_parse_fields+0xa15/0x1480
[ 1887.207836] btf_parse_struct_metas+0x566/0x670
[ 1887.208387] btf_new_fd+0x294/0x4d0
[ 1887.208851] __sys_bpf+0x4ba/0x600
[ 1887.209292] __x64_sys_bpf+0x41/0x50
[ 1887.209762] do_syscall_64+0x4c/0xf0
[ 1887.210222] entry_SYSCALL_64_after_hwframe+0x63/0x6b
[ 1887.210868]
[ 1887.211074] Freed by task 36:
[ 1887.211460] kasan_set_track+0x3f/0x60
[ 1887.211951] kasan_save_free_info+0x28/0x40
[ 1887.212485] ____kasan_slab_free+0x101/0x180
[ 1887.213027] __kmem_cache_free+0xe4/0x210
[ 1887.213514] btf_free+0x5b/0x130
[ 1887.213918] rcu_core+0x638/0xcc0
[ 1887.214347] __do_softirq+0x114/0x37e
The error happens at bpf_rb_root_free+0x1f8/0x2b0:
00000000000034c0 <bpf_rb_root_free>:
; {
34c0: f3 0f 1e fa endbr64
34c4: e8 00 00 00 00 callq 0x34c9 <bpf_rb_root_free+0x9>
34c9: 55 pushq %rbp
34ca: 48 89 e5 movq %rsp, %rbp
...
; if (rec && rec->refcount_off >= 0 &&
36aa: 4d 85 ed testq %r13, %r13
36ad: 74 a9 je 0x3658 <bpf_rb_root_free+0x198>
36af: 49 8d 7d 10 leaq 0x10(%r13), %rdi
36b3: e8 00 00 00 00 callq 0x36b8 <bpf_rb_root_free+0x1f8>
<==== kasan function
36b8: 45 8b 7d 10 movl 0x10(%r13), %r15d
<==== use-after-free load
36bc: 45 85 ff testl %r15d, %r15d
36bf: 78 8c js 0x364d <bpf_rb_root_free+0x18d>
So the problem
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
media: pvrusb2: fix use after free on context disconnection
Upon module load, a kthread is created targeting the
pvr2_context_thread_func function, which may call pvr2_context_destroy
and thus call kfree() on the context object. However, that might happen
before the usb hub_event handler is able to notify the driver. This
patch adds a sanity check before the invalid read reported by syzbot,
within the context disconnection call stack. |
| In the Linux kernel, the following vulnerability has been resolved:
binder: fix use-after-free in shinker's callback
The mmap read lock is used during the shrinker's callback, which means
that using alloc->vma pointer isn't safe as it can race with munmap().
As of commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in
munmap") the mmap lock is downgraded after the vma has been isolated.
I was able to reproduce this issue by manually adding some delays and
triggering page reclaiming through the shrinker's debug sysfs. The
following KASAN report confirms the UAF:
==================================================================
BUG: KASAN: slab-use-after-free in zap_page_range_single+0x470/0x4b8
Read of size 8 at addr ffff356ed50e50f0 by task bash/478
CPU: 1 PID: 478 Comm: bash Not tainted 6.6.0-rc5-00055-g1c8b86a3799f-dirty #70
Hardware name: linux,dummy-virt (DT)
Call trace:
zap_page_range_single+0x470/0x4b8
binder_alloc_free_page+0x608/0xadc
__list_lru_walk_one+0x130/0x3b0
list_lru_walk_node+0xc4/0x22c
binder_shrink_scan+0x108/0x1dc
shrinker_debugfs_scan_write+0x2b4/0x500
full_proxy_write+0xd4/0x140
vfs_write+0x1ac/0x758
ksys_write+0xf0/0x1dc
__arm64_sys_write+0x6c/0x9c
Allocated by task 492:
kmem_cache_alloc+0x130/0x368
vm_area_alloc+0x2c/0x190
mmap_region+0x258/0x18bc
do_mmap+0x694/0xa60
vm_mmap_pgoff+0x170/0x29c
ksys_mmap_pgoff+0x290/0x3a0
__arm64_sys_mmap+0xcc/0x144
Freed by task 491:
kmem_cache_free+0x17c/0x3c8
vm_area_free_rcu_cb+0x74/0x98
rcu_core+0xa38/0x26d4
rcu_core_si+0x10/0x1c
__do_softirq+0x2fc/0xd24
Last potentially related work creation:
__call_rcu_common.constprop.0+0x6c/0xba0
call_rcu+0x10/0x1c
vm_area_free+0x18/0x24
remove_vma+0xe4/0x118
do_vmi_align_munmap.isra.0+0x718/0xb5c
do_vmi_munmap+0xdc/0x1fc
__vm_munmap+0x10c/0x278
__arm64_sys_munmap+0x58/0x7c
Fix this issue by performing instead a vma_lookup() which will fail to
find the vma that was isolated before the mmap lock downgrade. Note that
this option has better performance than upgrading to a mmap write lock
which would increase contention. Plus, mmap_write_trylock() has been
recently removed anyway. |
