| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: Fix hci_suspend_sync crash
If hci_unregister_dev() frees the hci_dev object but hci_suspend_notifier
may still be accessing it, it can cause the program to crash.
Here's the call trace:
<4>[102152.653246] Call Trace:
<4>[102152.653254] hci_suspend_sync+0x109/0x301 [bluetooth]
<4>[102152.653259] hci_suspend_dev+0x78/0xcd [bluetooth]
<4>[102152.653263] hci_suspend_notifier+0x42/0x7a [bluetooth]
<4>[102152.653268] notifier_call_chain+0x43/0x6b
<4>[102152.653271] __blocking_notifier_call_chain+0x48/0x69
<4>[102152.653273] __pm_notifier_call_chain+0x22/0x39
<4>[102152.653276] pm_suspend+0x287/0x57c
<4>[102152.653278] state_store+0xae/0xe5
<4>[102152.653281] kernfs_fop_write+0x109/0x173
<4>[102152.653284] __vfs_write+0x16f/0x1a2
<4>[102152.653287] ? selinux_file_permission+0xca/0x16f
<4>[102152.653289] ? security_file_permission+0x36/0x109
<4>[102152.653291] vfs_write+0x114/0x21d
<4>[102152.653293] __x64_sys_write+0x7b/0xdb
<4>[102152.653296] do_syscall_64+0x59/0x194
<4>[102152.653299] entry_SYSCALL_64_after_hwframe+0x5c/0xc1
This patch holds the reference count of the hci_dev object while
processing it in hci_suspend_notifier to avoid potential crash
caused by the race condition. |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: fix disconnect vs accept race
Despite commit 0ad529d9fd2b ("mptcp: fix possible divide by zero in
recvmsg()"), the mptcp protocol is still prone to a race between
disconnect() (or shutdown) and accept.
The root cause is that the mentioned commit checks the msk-level
flag, but mptcp_stream_accept() does acquire the msk-level lock,
as it can rely directly on the first subflow lock.
As reported by Christoph than can lead to a race where an msk
socket is accepted after that mptcp_subflow_queue_clean() releases
the listener socket lock and just before it takes destructive
actions leading to the following splat:
BUG: kernel NULL pointer dereference, address: 0000000000000012
PGD 5a4ca067 P4D 5a4ca067 PUD 37d4c067 PMD 0
Oops: 0000 [#1] PREEMPT SMP
CPU: 2 PID: 10955 Comm: syz-executor.5 Not tainted 6.5.0-rc1-gdc7b257ee5dd #37
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
RIP: 0010:mptcp_stream_accept+0x1ee/0x2f0 include/net/inet_sock.h:330
Code: 0a 09 00 48 8b 1b 4c 39 e3 74 07 e8 bc 7c 7f fe eb a1 e8 b5 7c 7f fe 4c 8b 6c 24 08 eb 05 e8 a9 7c 7f fe 49 8b 85 d8 09 00 00 <0f> b6 40 12 88 44 24 07 0f b6 6c 24 07 bf 07 00 00 00 89 ee e8 89
RSP: 0018:ffffc90000d07dc0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888037e8d020 RCX: ffff88803b093300
RDX: 0000000000000000 RSI: ffffffff833822c5 RDI: ffffffff8333896a
RBP: 0000607f82031520 R08: ffff88803b093300 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000003e83 R12: ffff888037e8d020
R13: ffff888037e8c680 R14: ffff888009af7900 R15: ffff888009af6880
FS: 00007fc26d708640(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000012 CR3: 0000000066bc5001 CR4: 0000000000370ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
do_accept+0x1ae/0x260 net/socket.c:1872
__sys_accept4+0x9b/0x110 net/socket.c:1913
__do_sys_accept4 net/socket.c:1954 [inline]
__se_sys_accept4 net/socket.c:1951 [inline]
__x64_sys_accept4+0x20/0x30 net/socket.c:1951
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x47/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
Address the issue by temporary removing the pending request socket
from the accept queue, so that racing accept() can't touch them.
After depleting the msk - the ssk still exists, as plain TCP sockets,
re-insert them into the accept queue, so that later inet_csk_listen_stop()
will complete the tcp socket disposal. |
| In the Linux kernel, the following vulnerability has been resolved:
tracing/synthetic: Fix races on freeing last_cmd
Currently, the "last_cmd" variable can be accessed by multiple processes
asynchronously when multiple users manipulate synthetic_events node
at the same time, it could lead to use-after-free or double-free.
This patch add "lastcmd_mutex" to prevent "last_cmd" from being accessed
asynchronously.
================================================================
It's easy to reproduce in the KASAN environment by running the two
scripts below in different shells.
script 1:
while :
do
echo -n -e '\x88' > /sys/kernel/tracing/synthetic_events
done
script 2:
while :
do
echo -n -e '\xb0' > /sys/kernel/tracing/synthetic_events
done
================================================================
double-free scenario:
process A process B
------------------- ---------------
1.kstrdup last_cmd
2.free last_cmd
3.free last_cmd(double-free)
================================================================
use-after-free scenario:
process A process B
------------------- ---------------
1.kstrdup last_cmd
2.free last_cmd
3.tracing_log_err(use-after-free)
================================================================
Appendix 1. KASAN report double-free:
BUG: KASAN: double-free in kfree+0xdc/0x1d4
Free of addr ***** by task sh/4879
Call trace:
...
kfree+0xdc/0x1d4
create_or_delete_synth_event+0x60/0x1e8
trace_parse_run_command+0x2bc/0x4b8
synth_events_write+0x20/0x30
vfs_write+0x200/0x830
...
Allocated by task 4879:
...
kstrdup+0x5c/0x98
create_or_delete_synth_event+0x6c/0x1e8
trace_parse_run_command+0x2bc/0x4b8
synth_events_write+0x20/0x30
vfs_write+0x200/0x830
...
Freed by task 5464:
...
kfree+0xdc/0x1d4
create_or_delete_synth_event+0x60/0x1e8
trace_parse_run_command+0x2bc/0x4b8
synth_events_write+0x20/0x30
vfs_write+0x200/0x830
...
================================================================
Appendix 2. KASAN report use-after-free:
BUG: KASAN: use-after-free in strlen+0x5c/0x7c
Read of size 1 at addr ***** by task sh/5483
sh: CPU: 7 PID: 5483 Comm: sh
...
__asan_report_load1_noabort+0x34/0x44
strlen+0x5c/0x7c
tracing_log_err+0x60/0x444
create_or_delete_synth_event+0xc4/0x204
trace_parse_run_command+0x2bc/0x4b8
synth_events_write+0x20/0x30
vfs_write+0x200/0x830
...
Allocated by task 5483:
...
kstrdup+0x5c/0x98
create_or_delete_synth_event+0x80/0x204
trace_parse_run_command+0x2bc/0x4b8
synth_events_write+0x20/0x30
vfs_write+0x200/0x830
...
Freed by task 5480:
...
kfree+0xdc/0x1d4
create_or_delete_synth_event+0x74/0x204
trace_parse_run_command+0x2bc/0x4b8
synth_events_write+0x20/0x30
vfs_write+0x200/0x830
... |
| In the Linux kernel, the following vulnerability has been resolved:
mm: fix zswap writeback race condition
The zswap writeback mechanism can cause a race condition resulting in
memory corruption, where a swapped out page gets swapped in with data that
was written to a different page.
The race unfolds like this:
1. a page with data A and swap offset X is stored in zswap
2. page A is removed off the LRU by zpool driver for writeback in
zswap-shrink work, data for A is mapped by zpool driver
3. user space program faults and invalidates page entry A, offset X is
considered free
4. kswapd stores page B at offset X in zswap (zswap could also be
full, if so, page B would then be IOed to X, then skip step 5.)
5. entry A is replaced by B in tree->rbroot, this doesn't affect the
local reference held by zswap-shrink work
6. zswap-shrink work writes back A at X, and frees zswap entry A
7. swapin of slot X brings A in memory instead of B
The fix:
Once the swap page cache has been allocated (case ZSWAP_SWAPCACHE_NEW),
zswap-shrink work just checks that the local zswap_entry reference is
still the same as the one in the tree. If it's not the same it means that
it's either been invalidated or replaced, in both cases the writeback is
aborted because the local entry contains stale data.
Reproducer:
I originally found this by running `stress` overnight to validate my work
on the zswap writeback mechanism, it manifested after hours on my test
machine. The key to make it happen is having zswap writebacks, so
whatever setup pumps /sys/kernel/debug/zswap/written_back_pages should do
the trick.
In order to reproduce this faster on a vm, I setup a system with ~100M of
available memory and a 500M swap file, then running `stress --vm 1
--vm-bytes 300000000 --vm-stride 4000` makes it happen in matter of tens
of minutes. One can speed things up even more by swinging
/sys/module/zswap/parameters/max_pool_percent up and down between, say, 20
and 1; this makes it reproduce in tens of seconds. It's crucial to set
`--vm-stride` to something other than 4096 otherwise `stress` won't
realize that memory has been corrupted because all pages would have the
same data. |
| In the Linux kernel, the following vulnerability has been resolved:
tty: serial: fsl_lpuart: fix race on RX DMA shutdown
From time to time DMA completion can come in the middle of DMA shutdown:
<process ctx>: <IRQ>:
lpuart32_shutdown()
lpuart_dma_shutdown()
del_timer_sync()
lpuart_dma_rx_complete()
lpuart_copy_rx_to_tty()
mod_timer()
lpuart_dma_rx_free()
When the timer fires a bit later, sport->dma_rx_desc is NULL:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004
pc : lpuart_copy_rx_to_tty+0xcc/0x5bc
lr : lpuart_timer_func+0x1c/0x2c
Call trace:
lpuart_copy_rx_to_tty
lpuart_timer_func
call_timer_fn
__run_timers.part.0
run_timer_softirq
__do_softirq
__irq_exit_rcu
irq_exit
handle_domain_irq
gic_handle_irq
call_on_irq_stack
do_interrupt_handler
...
To fix this fold del_timer_sync() into lpuart_dma_rx_free() after
dmaengine_terminate_sync() to make sure timer will not be re-started in
lpuart_copy_rx_to_tty() <= lpuart_dma_rx_complete(). |
| In the Linux kernel, the following vulnerability has been resolved:
tee: amdtee: fix race condition in amdtee_open_session
There is a potential race condition in amdtee_open_session that may
lead to use-after-free. For instance, in amdtee_open_session() after
sess->sess_mask is set, and before setting:
sess->session_info[i] = session_info;
if amdtee_close_session() closes this same session, then 'sess' data
structure will be released, causing kernel panic when 'sess' is
accessed within amdtee_open_session().
The solution is to set the bit sess->sess_mask as the last step in
amdtee_open_session(). |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: Fix race condition in hci_cmd_sync_clear
There is a potential race condition in hci_cmd_sync_work and
hci_cmd_sync_clear, and could lead to use-after-free. For instance,
hci_cmd_sync_work is added to the 'req_workqueue' after cancel_work_sync
The entry of 'cmd_sync_work_list' may be freed in hci_cmd_sync_clear, and
causing kernel panic when it is used in 'hci_cmd_sync_work'.
Here's the call trace:
dump_stack_lvl+0x49/0x63
print_report.cold+0x5e/0x5d3
? hci_cmd_sync_work+0x282/0x320
kasan_report+0xaa/0x120
? hci_cmd_sync_work+0x282/0x320
__asan_report_load8_noabort+0x14/0x20
hci_cmd_sync_work+0x282/0x320
process_one_work+0x77b/0x11c0
? _raw_spin_lock_irq+0x8e/0xf0
worker_thread+0x544/0x1180
? poll_idle+0x1e0/0x1e0
kthread+0x285/0x320
? process_one_work+0x11c0/0x11c0
? kthread_complete_and_exit+0x30/0x30
ret_from_fork+0x22/0x30
</TASK>
Allocated by task 266:
kasan_save_stack+0x26/0x50
__kasan_kmalloc+0xae/0xe0
kmem_cache_alloc_trace+0x191/0x350
hci_cmd_sync_queue+0x97/0x2b0
hci_update_passive_scan+0x176/0x1d0
le_conn_complete_evt+0x1b5/0x1a00
hci_le_conn_complete_evt+0x234/0x340
hci_le_meta_evt+0x231/0x4e0
hci_event_packet+0x4c5/0xf00
hci_rx_work+0x37d/0x880
process_one_work+0x77b/0x11c0
worker_thread+0x544/0x1180
kthread+0x285/0x320
ret_from_fork+0x22/0x30
Freed by task 269:
kasan_save_stack+0x26/0x50
kasan_set_track+0x25/0x40
kasan_set_free_info+0x24/0x40
____kasan_slab_free+0x176/0x1c0
__kasan_slab_free+0x12/0x20
slab_free_freelist_hook+0x95/0x1a0
kfree+0xba/0x2f0
hci_cmd_sync_clear+0x14c/0x210
hci_unregister_dev+0xff/0x440
vhci_release+0x7b/0xf0
__fput+0x1f3/0x970
____fput+0xe/0x20
task_work_run+0xd4/0x160
do_exit+0x8b0/0x22a0
do_group_exit+0xba/0x2a0
get_signal+0x1e4a/0x25b0
arch_do_signal_or_restart+0x93/0x1f80
exit_to_user_mode_prepare+0xf5/0x1a0
syscall_exit_to_user_mode+0x26/0x50
ret_from_fork+0x15/0x30 |
| In the Linux kernel, the following vulnerability has been resolved:
mm/MADV_COLLAPSE: catch !none !huge !bad pmd lookups
In commit 34488399fa08 ("mm/madvise: add file and shmem support to
MADV_COLLAPSE") we make the following change to find_pmd_or_thp_or_none():
- if (!pmd_present(pmde))
- return SCAN_PMD_NULL;
+ if (pmd_none(pmde))
+ return SCAN_PMD_NONE;
This was for-use by MADV_COLLAPSE file/shmem codepaths, where
MADV_COLLAPSE might identify a pte-mapped hugepage, only to have
khugepaged race-in, free the pte table, and clear the pmd. Such codepaths
include:
A) If we find a suitably-aligned compound page of order HPAGE_PMD_ORDER
already in the pagecache.
B) In retract_page_tables(), if we fail to grab mmap_lock for the target
mm/address.
In these cases, collapse_pte_mapped_thp() really does expect a none (not
just !present) pmd, and we want to suitably identify that case separate
from the case where no pmd is found, or it's a bad-pmd (of course, many
things could happen once we drop mmap_lock, and the pmd could plausibly
undergo multiple transitions due to intervening fault, split, etc).
Regardless, the code is prepared install a huge-pmd only when the existing
pmd entry is either a genuine pte-table-mapping-pmd, or the none-pmd.
However, the commit introduces a logical hole; namely, that we've allowed
!none- && !huge- && !bad-pmds to be classified as genuine
pte-table-mapping-pmds. One such example that could leak through are swap
entries. The pmd values aren't checked again before use in
pte_offset_map_lock(), which is expecting nothing less than a genuine
pte-table-mapping-pmd.
We want to put back the !pmd_present() check (below the pmd_none() check),
but need to be careful to deal with subtleties in pmd transitions and
treatments by various arch.
The issue is that __split_huge_pmd_locked() temporarily clears the present
bit (or otherwise marks the entry as invalid), but pmd_present() and
pmd_trans_huge() still need to return true while the pmd is in this
transitory state. For example, x86's pmd_present() also checks the
_PAGE_PSE , riscv's version also checks the _PAGE_LEAF bit, and arm64 also
checks a PMD_PRESENT_INVALID bit.
Covering all 4 cases for x86 (all checks done on the same pmd value):
1) pmd_present() && pmd_trans_huge()
All we actually know here is that the PSE bit is set. Either:
a) We aren't racing with __split_huge_page(), and PRESENT or PROTNONE
is set.
=> huge-pmd
b) We are currently racing with __split_huge_page(). The danger here
is that we proceed as-if we have a huge-pmd, but really we are
looking at a pte-mapping-pmd. So, what is the risk of this
danger?
The only relevant path is:
madvise_collapse() -> collapse_pte_mapped_thp()
Where we might just incorrectly report back "success", when really
the memory isn't pmd-backed. This is fine, since split could
happen immediately after (actually) successful madvise_collapse().
So, it should be safe to just assume huge-pmd here.
2) pmd_present() && !pmd_trans_huge()
Either:
a) PSE not set and either PRESENT or PROTNONE is.
=> pte-table-mapping pmd (or PROT_NONE)
b) devmap. This routine can be called immediately after
unlocking/locking mmap_lock -- or called with no locks held (see
khugepaged_scan_mm_slot()), so previous VMA checks have since been
invalidated.
3) !pmd_present() && pmd_trans_huge()
Not possible.
4) !pmd_present() && !pmd_trans_huge()
Neither PRESENT nor PROTNONE set
=> not present
I've checked all archs that implement pmd_trans_huge() (arm64, riscv,
powerpc, longarch, x86, mips, s390) and this logic roughly translates
(though devmap treatment is unique to x86 and powerpc, and (3) doesn't
necessarily hold in general -- but that doesn't matter since
!pmd_present() always takes failure path).
Also, add a comment above find_pmd_or_thp_or_none()
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
fs: dlm: fix race in lowcomms
This patch fixes a race between queue_work() in
_dlm_lowcomms_commit_msg() and srcu_read_unlock(). The queue_work() can
take the final reference of a dlm_msg and so msg->idx can contain
garbage which is signaled by the following warning:
[ 676.237050] ------------[ cut here ]------------
[ 676.237052] WARNING: CPU: 0 PID: 1060 at include/linux/srcu.h:189 dlm_lowcomms_commit_msg+0x41/0x50
[ 676.238945] Modules linked in: dlm_locktorture torture rpcsec_gss_krb5 intel_rapl_msr intel_rapl_common iTCO_wdt iTCO_vendor_support qxl kvm_intel drm_ttm_helper vmw_vsock_virtio_transport kvm vmw_vsock_virtio_transport_common ttm irqbypass crc32_pclmul joydev crc32c_intel serio_raw drm_kms_helper vsock virtio_scsi virtio_console virtio_balloon snd_pcm drm syscopyarea sysfillrect sysimgblt snd_timer fb_sys_fops i2c_i801 lpc_ich snd i2c_smbus soundcore pcspkr
[ 676.244227] CPU: 0 PID: 1060 Comm: lock_torture_wr Not tainted 5.19.0-rc3+ #1546
[ 676.245216] Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.16.0-2.module+el8.7.0+15506+033991b0 04/01/2014
[ 676.246460] RIP: 0010:dlm_lowcomms_commit_msg+0x41/0x50
[ 676.247132] Code: fe ff ff ff 75 24 48 c7 c6 bd 0f 49 bb 48 c7 c7 38 7c 01 bd e8 00 e7 ca ff 89 de 48 c7 c7 60 78 01 bd e8 42 3d cd ff 5b 5d c3 <0f> 0b eb d8 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48
[ 676.249253] RSP: 0018:ffffa401c18ffc68 EFLAGS: 00010282
[ 676.249855] RAX: 0000000000000001 RBX: 00000000ffff8b76 RCX: 0000000000000006
[ 676.250713] RDX: 0000000000000000 RSI: ffffffffbccf3a10 RDI: ffffffffbcc7b62e
[ 676.251610] RBP: ffffa401c18ffc70 R08: 0000000000000001 R09: 0000000000000001
[ 676.252481] R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000005
[ 676.253421] R13: ffff8b76786ec370 R14: ffff8b76786ec370 R15: ffff8b76786ec480
[ 676.254257] FS: 0000000000000000(0000) GS:ffff8b7777800000(0000) knlGS:0000000000000000
[ 676.255239] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 676.255897] CR2: 00005590205d88b8 CR3: 000000017656c003 CR4: 0000000000770ee0
[ 676.256734] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 676.257567] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 676.258397] PKRU: 55555554
[ 676.258729] Call Trace:
[ 676.259063] <TASK>
[ 676.259354] dlm_midcomms_commit_mhandle+0xcc/0x110
[ 676.259964] queue_bast+0x8b/0xb0
[ 676.260423] grant_pending_locks+0x166/0x1b0
[ 676.261007] _unlock_lock+0x75/0x90
[ 676.261469] unlock_lock.isra.57+0x62/0xa0
[ 676.262009] dlm_unlock+0x21e/0x330
[ 676.262457] ? lock_torture_stats+0x80/0x80 [dlm_locktorture]
[ 676.263183] torture_unlock+0x5a/0x90 [dlm_locktorture]
[ 676.263815] ? preempt_count_sub+0xba/0x100
[ 676.264361] ? complete+0x1d/0x60
[ 676.264777] lock_torture_writer+0xb8/0x150 [dlm_locktorture]
[ 676.265555] kthread+0x10a/0x130
[ 676.266007] ? kthread_complete_and_exit+0x20/0x20
[ 676.266616] ret_from_fork+0x22/0x30
[ 676.267097] </TASK>
[ 676.267381] irq event stamp: 9579855
[ 676.267824] hardirqs last enabled at (9579863): [<ffffffffbb14e6f8>] __up_console_sem+0x58/0x60
[ 676.268896] hardirqs last disabled at (9579872): [<ffffffffbb14e6dd>] __up_console_sem+0x3d/0x60
[ 676.270008] softirqs last enabled at (9579798): [<ffffffffbc200349>] __do_softirq+0x349/0x4c7
[ 676.271438] softirqs last disabled at (9579897): [<ffffffffbb0d54c0>] irq_exit_rcu+0xb0/0xf0
[ 676.272796] ---[ end trace 0000000000000000 ]---
I reproduced this warning with dlm_locktorture test which is currently
not upstream. However this patch fix the issue by make a additional
refcount between dlm_lowcomms_new_msg() and dlm_lowcomms_commit_msg().
In case of the race the kref_put() in dlm_lowcomms_commit_msg() will be
the final put. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: target: iscsi: Fix a race condition between login_work and the login thread
In case a malicious initiator sends some random data immediately after a
login PDU; the iscsi_target_sk_data_ready() callback will schedule the
login_work and, at the same time, the negotiation may end without clearing
the LOGIN_FLAGS_INITIAL_PDU flag (because no additional PDU exchanges are
required to complete the login).
The login has been completed but the login_work function will find the
LOGIN_FLAGS_INITIAL_PDU flag set and will never stop from rescheduling
itself; at this point, if the initiator drops the connection, the
iscsit_conn structure will be freed, login_work will dereference a released
socket structure and the kernel crashes.
BUG: kernel NULL pointer dereference, address: 0000000000000230
PF: supervisor write access in kernel mode
PF: error_code(0x0002) - not-present page
Workqueue: events iscsi_target_do_login_rx [iscsi_target_mod]
RIP: 0010:_raw_read_lock_bh+0x15/0x30
Call trace:
iscsi_target_do_login_rx+0x75/0x3f0 [iscsi_target_mod]
process_one_work+0x1e8/0x3c0
Fix this bug by forcing login_work to stop after the login has been
completed and the socket callbacks have been restored.
Add a comment to clearify the return values of iscsi_target_do_login() |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: avoid hci_dev_test_and_set_flag() in mgmt_init_hdev()
syzbot is again reporting attempt to cancel uninitialized work
at mgmt_index_removed() [1], for setting of HCI_MGMT flag from
mgmt_init_hdev() from hci_mgmt_cmd() from hci_sock_sendmsg() can
race with testing of HCI_MGMT flag from mgmt_index_removed() from
hci_sock_bind() due to lack of serialization via hci_dev_lock().
Since mgmt_init_hdev() is called with mgmt_chan_list_lock held, we can
safely split hci_dev_test_and_set_flag() into hci_dev_test_flag() and
hci_dev_set_flag(). Thus, in order to close this race, set HCI_MGMT flag
after INIT_DELAYED_WORK() completed.
This is a local fix based on mgmt_chan_list_lock. Lack of serialization
via hci_dev_lock() might be causing different race conditions somewhere
else. But a global fix based on hci_dev_lock() should deserve a future
patch. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/gup: fix FOLL_FORCE COW security issue and remove FOLL_COW
Ever since the Dirty COW (CVE-2016-5195) security issue happened, we know
that FOLL_FORCE can be possibly dangerous, especially if there are races
that can be exploited by user space.
Right now, it would be sufficient to have some code that sets a PTE of a
R/O-mapped shared page dirty, in order for it to erroneously become
writable by FOLL_FORCE. The implications of setting a write-protected PTE
dirty might not be immediately obvious to everyone.
And in fact ever since commit 9ae0f87d009c ("mm/shmem: unconditionally set
pte dirty in mfill_atomic_install_pte"), we can use UFFDIO_CONTINUE to map
a shmem page R/O while marking the pte dirty. This can be used by
unprivileged user space to modify tmpfs/shmem file content even if the
user does not have write permissions to the file, and to bypass memfd
write sealing -- Dirty COW restricted to tmpfs/shmem (CVE-2022-2590).
To fix such security issues for good, the insight is that we really only
need that fancy retry logic (FOLL_COW) for COW mappings that are not
writable (!VM_WRITE). And in a COW mapping, we really only broke COW if
we have an exclusive anonymous page mapped. If we have something else
mapped, or the mapped anonymous page might be shared (!PageAnonExclusive),
we have to trigger a write fault to break COW. If we don't find an
exclusive anonymous page when we retry, we have to trigger COW breaking
once again because something intervened.
Let's move away from this mandatory-retry + dirty handling and rely on our
PageAnonExclusive() flag for making a similar decision, to use the same
COW logic as in other kernel parts here as well. In case we stumble over
a PTE in a COW mapping that does not map an exclusive anonymous page, COW
was not properly broken and we have to trigger a fake write-fault to break
COW.
Just like we do in can_change_pte_writable() added via commit 64fe24a3e05e
("mm/mprotect: try avoiding write faults for exclusive anonymous pages
when changing protection") and commit 76aefad628aa ("mm/mprotect: fix
soft-dirty check in can_change_pte_writable()"), take care of softdirty
and uffd-wp manually.
For example, a write() via /proc/self/mem to a uffd-wp-protected range has
to fail instead of silently granting write access and bypassing the
userspace fault handler. Note that FOLL_FORCE is not only used for debug
access, but also triggered by applications without debug intentions, for
example, when pinning pages via RDMA.
This fixes CVE-2022-2590. Note that only x86_64 and aarch64 are
affected, because only those support CONFIG_HAVE_ARCH_USERFAULTFD_MINOR.
Fortunately, FOLL_COW is no longer required to handle FOLL_FORCE. So
let's just get rid of it.
Thanks to Nadav Amit for pointing out that the pte_dirty() check in
FOLL_FORCE code is problematic and might be exploitable.
Note 1: We don't check for the PTE being dirty because it doesn't matter
for making a "was COWed" decision anymore, and whoever modifies the
page has to set the page dirty either way.
Note 2: Kernels before extended uffd-wp support and before
PageAnonExclusive (< 5.19) can simply revert the problematic
commit instead and be safe regarding UFFDIO_CONTINUE. A backport to
v5.19 requires minor adjustments due to lack of
vma_soft_dirty_enabled(). |
| In the Linux kernel, the following vulnerability has been resolved:
ieee802154/adf7242: defer destroy_workqueue call
There is a possible race condition (use-after-free) like below
(FREE) | (USE)
adf7242_remove | adf7242_channel
cancel_delayed_work_sync |
destroy_workqueue (1) | adf7242_cmd_rx
| mod_delayed_work (2)
|
The root cause for this race is that the upper layer (ieee802154) is
unaware of this detaching event and the function adf7242_channel can
be called without any checks.
To fix this, we can add a flag write at the beginning of adf7242_remove
and add flag check in adf7242_channel. Or we can just defer the
destructive operation like other commit 3e0588c291d6 ("hamradio: defer
ax25 kfree after unregister_netdev") which let the
ieee802154_unregister_hw() to handle the synchronization. This patch
takes the second option.
runs") |
| In the Linux kernel, the following vulnerability has been resolved:
binder: fix UAF of ref->proc caused by race condition
A transaction of type BINDER_TYPE_WEAK_HANDLE can fail to increment the
reference for a node. In this case, the target proc normally releases
the failed reference upon close as expected. However, if the target is
dying in parallel the call will race with binder_deferred_release(), so
the target could have released all of its references by now leaving the
cleanup of the new failed reference unhandled.
The transaction then ends and the target proc gets released making the
ref->proc now a dangling pointer. Later on, ref->node is closed and we
attempt to take spin_lock(&ref->proc->inner_lock), which leads to the
use-after-free bug reported below. Let's fix this by cleaning up the
failed reference on the spot instead of relying on the target to do so.
==================================================================
BUG: KASAN: use-after-free in _raw_spin_lock+0xa8/0x150
Write of size 4 at addr ffff5ca207094238 by task kworker/1:0/590
CPU: 1 PID: 590 Comm: kworker/1:0 Not tainted 5.19.0-rc8 #10
Hardware name: linux,dummy-virt (DT)
Workqueue: events binder_deferred_func
Call trace:
dump_backtrace.part.0+0x1d0/0x1e0
show_stack+0x18/0x70
dump_stack_lvl+0x68/0x84
print_report+0x2e4/0x61c
kasan_report+0xa4/0x110
kasan_check_range+0xfc/0x1a4
__kasan_check_write+0x3c/0x50
_raw_spin_lock+0xa8/0x150
binder_deferred_func+0x5e0/0x9b0
process_one_work+0x38c/0x5f0
worker_thread+0x9c/0x694
kthread+0x188/0x190
ret_from_fork+0x10/0x20 |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: netlink notifier might race to release objects
commit release path is invoked via call_rcu and it runs lockless to
release the objects after rcu grace period. The netlink notifier handler
might win race to remove objects that the transaction context is still
referencing from the commit release path.
Call rcu_barrier() to ensure pending rcu callbacks run to completion
if the list of transactions to be destroyed is not empty. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: release flow rule object from commit path
No need to postpone this to the commit release path, since no packets
are walking over this object, this is accessed from control plane only.
This helped uncovered UAF triggered by races with the netlink notifier. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: Initialize gfn_to_pfn_cache locks in dedicated helper
Move the gfn_to_pfn_cache lock initialization to another helper and
call the new helper during VM/vCPU creation. There are race
conditions possible due to kvm_gfn_to_pfn_cache_init()'s
ability to re-initialize the cache's locks.
For example: a race between ioctl(KVM_XEN_HVM_EVTCHN_SEND) and
kvm_gfn_to_pfn_cache_init() leads to a corrupted shinfo gpc lock.
(thread 1) | (thread 2)
|
kvm_xen_set_evtchn_fast |
read_lock_irqsave(&gpc->lock, ...) |
| kvm_gfn_to_pfn_cache_init
| rwlock_init(&gpc->lock)
read_unlock_irqrestore(&gpc->lock, ...) |
Rename "cache_init" and "cache_destroy" to activate+deactivate to
avoid implying that the cache really is destroyed/freed.
Note, there more races in the newly named kvm_gpc_activate() that will
be addressed separately.
[sean: call out that this is a bug fix] |
| In the Linux kernel, the following vulnerability has been resolved:
kcm: close race conditions on sk_receive_queue
sk->sk_receive_queue is protected by skb queue lock, but for KCM
sockets its RX path takes mux->rx_lock to protect more than just
skb queue. However, kcm_recvmsg() still only grabs the skb queue
lock, so race conditions still exist.
We can teach kcm_recvmsg() to grab mux->rx_lock too but this would
introduce a potential performance regression as struct kcm_mux can
be shared by multiple KCM sockets.
So we have to enforce skb queue lock in requeue_rx_msgs() and handle
skb peek case carefully in kcm_wait_data(). Fortunately,
skb_recv_datagram() already handles it nicely and is widely used by
other sockets, we can just switch to skb_recv_datagram() after
getting rid of the unnecessary sock lock in kcm_recvmsg() and
kcm_splice_read(). Side note: SOCK_DONE is not used by KCM sockets,
so it is safe to get rid of this check too.
I ran the original syzbot reproducer for 30 min without seeing any
issue. |
| A race condition was addressed with improved state handling. This issue is fixed in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.6. An app may be able to gain root privileges. |
| A race condition was addressed with improved state management. This issue is fixed in macOS Sonoma 14.8.8, macOS Tahoe 26.6. An app may be able to gain root privileges. |
