Security Vulnerabilities
- CVEs Published In August 2024
In the Linux kernel, the following vulnerability has been resolved:
md/raid5: avoid BUG_ON() while continue reshape after reassembling
Currently, mdadm support --revert-reshape to abort the reshape while
reassembling, as the test 07revert-grow. However, following BUG_ON()
can be triggerred by the test:
kernel BUG at drivers/md/raid5.c:6278!
invalid opcode: 0000 [#1] PREEMPT SMP PTI
irq event stamp: 158985
CPU: 6 PID: 891 Comm: md0_reshape Not tainted 6.9.0-03335-g7592a0b0049a #94
RIP: 0010:reshape_request+0x3f1/0xe60
Call Trace:
<TASK>
raid5_sync_request+0x43d/0x550
md_do_sync+0xb7a/0x2110
md_thread+0x294/0x2b0
kthread+0x147/0x1c0
ret_from_fork+0x59/0x70
ret_from_fork_asm+0x1a/0x30
</TASK>
Root cause is that --revert-reshape update the raid_disks from 5 to 4,
while reshape position is still set, and after reassembling the array,
reshape position will be read from super block, then during reshape the
checking of 'writepos' that is caculated by old reshape position will
fail.
Fix this panic the easy way first, by converting the BUG_ON() to
WARN_ON(), and stop the reshape if checkings fail.
Noted that mdadm must fix --revert-shape as well, and probably md/raid
should enhance metadata validation as well, however this means
reassemble will fail and there must be user tools to fix the wrong
metadata.
In the Linux kernel, the following vulnerability has been resolved:
gpio: prevent potential speculation leaks in gpio_device_get_desc()
Userspace may trigger a speculative read of an address outside the gpio
descriptor array.
Users can do that by calling gpio_ioctl() with an offset out of range.
Offset is copied from user and then used as an array index to get
the gpio descriptor without sanitization in gpio_device_get_desc().
This change ensures that the offset is sanitized by using
array_index_nospec() to mitigate any possibility of speculative
information leaks.
This bug was discovered and resolved using Coverity Static Analysis
Security Testing (SAST) by Synopsys, Inc.
In the Linux kernel, the following vulnerability has been resolved:
idpf: fix UAFs when destroying the queues
The second tagged commit started sometimes (very rarely, but possible)
throwing WARNs from
net/core/page_pool.c:page_pool_disable_direct_recycling().
Turned out idpf frees interrupt vectors with embedded NAPIs *before*
freeing the queues making page_pools' NAPI pointers lead to freed
memory before these pools are destroyed by libeth.
It's not clear whether there are other accesses to the freed vectors
when destroying the queues, but anyway, we usually free queue/interrupt
vectors only when the queues are destroyed and the NAPIs are guaranteed
to not be referenced anywhere.
Invert the allocation and freeing logic making queue/interrupt vectors
be allocated first and freed last. Vectors don't require queues to be
present, so this is safe. Additionally, this change allows to remove
that useless queue->q_vector pointer cleanup, as vectors are still
valid when freeing the queues (+ both are freed within one function,
so it's not clear why nullify the pointers at all).
In the Linux kernel, the following vulnerability has been resolved:
bnxt_en : Fix memory out-of-bounds in bnxt_fill_hw_rss_tbl()
A recent commit has modified the code in __bnxt_reserve_rings() to
set the default RSS indirection table to default only when the number
of RX rings is changing. While this works for newer firmware that
requires RX ring reservations, it causes the regression on older
firmware not requiring RX ring resrvations (BNXT_NEW_RM() returns
false).
With older firmware, RX ring reservations are not required and so
hw_resc->resv_rx_rings is not always set to the proper value. The
comparison:
if (old_rx_rings != bp->hw_resc.resv_rx_rings)
in __bnxt_reserve_rings() may be false even when the RX rings are
changing. This will cause __bnxt_reserve_rings() to skip setting
the default RSS indirection table to default to match the current
number of RX rings. This may later cause bnxt_fill_hw_rss_tbl() to
use an out-of-range index.
We already have bnxt_check_rss_tbl_no_rmgr() to handle exactly this
scenario. We just need to move it up in bnxt_need_reserve_rings()
to be called unconditionally when using older firmware. Without the
fix, if the TX rings are changing, we'll skip the
bnxt_check_rss_tbl_no_rmgr() call and __bnxt_reserve_rings() may also
skip the bnxt_set_dflt_rss_indir_tbl() call for the reason explained
in the last paragraph. Without setting the default RSS indirection
table to default, it causes the regression:
BUG: KASAN: slab-out-of-bounds in __bnxt_hwrm_vnic_set_rss+0xb79/0xe40
Read of size 2 at addr ffff8881c5809618 by task ethtool/31525
Call Trace:
__bnxt_hwrm_vnic_set_rss+0xb79/0xe40
bnxt_hwrm_vnic_rss_cfg_p5+0xf7/0x460
__bnxt_setup_vnic_p5+0x12e/0x270
__bnxt_open_nic+0x2262/0x2f30
bnxt_open_nic+0x5d/0xf0
ethnl_set_channels+0x5d4/0xb30
ethnl_default_set_doit+0x2f1/0x620
In the Linux kernel, the following vulnerability has been resolved:
net: bridge: mcast: wait for previous gc cycles when removing port
syzbot hit a use-after-free[1] which is caused because the bridge doesn't
make sure that all previous garbage has been collected when removing a
port. What happens is:
CPU 1 CPU 2
start gc cycle remove port
acquire gc lock first
wait for lock
call br_multicasg_gc() directly
acquire lock now but free port
the port can be freed
while grp timers still
running
Make sure all previous gc cycles have finished by using flush_work before
freeing the port.
[1]
BUG: KASAN: slab-use-after-free in br_multicast_port_group_expired+0x4c0/0x550 net/bridge/br_multicast.c:861
Read of size 8 at addr ffff888071d6d000 by task syz.5.1232/9699
CPU: 1 PID: 9699 Comm: syz.5.1232 Not tainted 6.10.0-rc5-syzkaller-00021-g24ca36a562d6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
print_address_description mm/kasan/report.c:377 [inline]
print_report+0xc3/0x620 mm/kasan/report.c:488
kasan_report+0xd9/0x110 mm/kasan/report.c:601
br_multicast_port_group_expired+0x4c0/0x550 net/bridge/br_multicast.c:861
call_timer_fn+0x1a3/0x610 kernel/time/timer.c:1792
expire_timers kernel/time/timer.c:1843 [inline]
__run_timers+0x74b/0xaf0 kernel/time/timer.c:2417
__run_timer_base kernel/time/timer.c:2428 [inline]
__run_timer_base kernel/time/timer.c:2421 [inline]
run_timer_base+0x111/0x190 kernel/time/timer.c:2437
In the Linux kernel, the following vulnerability has been resolved:
sctp: Fix null-ptr-deref in reuseport_add_sock().
syzbot reported a null-ptr-deref while accessing sk2->sk_reuseport_cb in
reuseport_add_sock(). [0]
The repro first creates a listener with SO_REUSEPORT. Then, it creates
another listener on the same port and concurrently closes the first
listener.
The second listen() calls reuseport_add_sock() with the first listener as
sk2, where sk2->sk_reuseport_cb is not expected to be cleared concurrently,
but the close() does clear it by reuseport_detach_sock().
The problem is SCTP does not properly synchronise reuseport_alloc(),
reuseport_add_sock(), and reuseport_detach_sock().
The caller of reuseport_alloc() and reuseport_{add,detach}_sock() must
provide synchronisation for sockets that are classified into the same
reuseport group.
Otherwise, such sockets form multiple identical reuseport groups, and
all groups except one would be silently dead.
1. Two sockets call listen() concurrently
2. No socket in the same group found in sctp_ep_hashtable[]
3. Two sockets call reuseport_alloc() and form two reuseport groups
4. Only one group hit first in __sctp_rcv_lookup_endpoint() receives
incoming packets
Also, the reported null-ptr-deref could occur.
TCP/UDP guarantees that would not happen by holding the hash bucket lock.
Let's apply the locking strategy to __sctp_hash_endpoint() and
__sctp_unhash_endpoint().
[0]:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 1 UID: 0 PID: 10230 Comm: syz-executor119 Not tainted 6.10.0-syzkaller-12585-g301927d2d2eb #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
RIP: 0010:reuseport_add_sock+0x27e/0x5e0 net/core/sock_reuseport.c:350
Code: 00 0f b7 5d 00 bf 01 00 00 00 89 de e8 1b a4 ff f7 83 fb 01 0f 85 a3 01 00 00 e8 6d a0 ff f7 49 8d 7e 12 48 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 4b 02 00 00 41 0f b7 5e 12 49 8d 7e 14
RSP: 0018:ffffc9000b947c98 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffff8880252ddf98 RCX: ffff888079478000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000012
RBP: 0000000000000001 R08: ffffffff8993e18d R09: 1ffffffff1fef385
R10: dffffc0000000000 R11: fffffbfff1fef386 R12: ffff8880252ddac0
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f24e45b96c0(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffcced5f7b8 CR3: 00000000241be000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__sctp_hash_endpoint net/sctp/input.c:762 [inline]
sctp_hash_endpoint+0x52a/0x600 net/sctp/input.c:790
sctp_listen_start net/sctp/socket.c:8570 [inline]
sctp_inet_listen+0x767/0xa20 net/sctp/socket.c:8625
__sys_listen_socket net/socket.c:1883 [inline]
__sys_listen+0x1b7/0x230 net/socket.c:1894
__do_sys_listen net/socket.c:1902 [inline]
__se_sys_listen net/socket.c:1900 [inline]
__x64_sys_listen+0x5a/0x70 net/socket.c:1900
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f24e46039b9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 91 1a 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:00007f24e45b9228 EFLAGS: 00000246 ORIG_RAX: 0000000000000032
RAX: ffffffffffffffda RBX: 00007f24e468e428 RCX: 00007f24e46039b9
RDX: 00007f24e46039b9 RSI: 0000000000000003 RDI: 0000000000000004
RBP: 00007f24e468e420 R08: 00007f24e45b96c0 R09: 00007f24e45b96c0
R10: 00007f24e45b96c0 R11: 0000000000000246 R12: 00007f24e468e42c
R13:
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
power: supply: rt5033: Bring back i2c_set_clientdata
Commit 3a93da231c12 ("power: supply: rt5033: Use devm_power_supply_register() helper")
reworked the driver to use devm. While at it, the i2c_set_clientdata
was dropped along with the remove callback. Unfortunately other parts
of the driver also rely on i2c clientdata so this causes kernel oops.
Bring the call back to fix the driver.
In the Linux kernel, the following vulnerability has been resolved:
platform/x86: intel-vbtn: Protect ACPI notify handler against recursion
Since commit e2ffcda16290 ("ACPI: OSL: Allow Notify () handlers to run on
all CPUs") ACPI notify handlers like the intel-vbtn notify_handler() may
run on multiple CPU cores racing with themselves.
This race gets hit on Dell Venue 7140 tablets when undocking from
the keyboard, causing the handler to try and register priv->switches_dev
twice, as can be seen from the dev_info() message getting logged twice:
[ 83.861800] intel-vbtn INT33D6:00: Registering Intel Virtual Switches input-dev after receiving a switch event
[ 83.861858] input: Intel Virtual Switches as /devices/pci0000:00/0000:00:1f.0/PNP0C09:00/INT33D6:00/input/input17
[ 83.861865] intel-vbtn INT33D6:00: Registering Intel Virtual Switches input-dev after receiving a switch event
After which things go seriously wrong:
[ 83.861872] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:1f.0/PNP0C09:00/INT33D6:00/input/input17'
...
[ 83.861967] kobject: kobject_add_internal failed for input17 with -EEXIST, don't try to register things with the same name in the same directory.
[ 83.877338] BUG: kernel NULL pointer dereference, address: 0000000000000018
...
Protect intel-vbtn notify_handler() from racing with itself with a mutex
to fix this.
In the Linux kernel, the following vulnerability has been resolved:
tracing: Fix overflow in get_free_elt()
"tracing_map->next_elt" in get_free_elt() is at risk of overflowing.
Once it overflows, new elements can still be inserted into the tracing_map
even though the maximum number of elements (`max_elts`) has been reached.
Continuing to insert elements after the overflow could result in the
tracing_map containing "tracing_map->max_size" elements, leaving no empty
entries.
If any attempt is made to insert an element into a full tracing_map using
`__tracing_map_insert()`, it will cause an infinite loop with preemption
disabled, leading to a CPU hang problem.
Fix this by preventing any further increments to "tracing_map->next_elt"
once it reaches "tracing_map->max_elt".
In the Linux kernel, the following vulnerability has been resolved:
tracing: Have format file honor EVENT_FILE_FL_FREED
When eventfs was introduced, special care had to be done to coordinate the
freeing of the file meta data with the files that are exposed to user
space. The file meta data would have a ref count that is set when the file
is created and would be decremented and freed after the last user that
opened the file closed it. When the file meta data was to be freed, it
would set a flag (EVENT_FILE_FL_FREED) to denote that the file is freed,
and any new references made (like new opens or reads) would fail as it is
marked freed. This allowed other meta data to be freed after this flag was
set (under the event_mutex).
All the files that were dynamically created in the events directory had a
pointer to the file meta data and would call event_release() when the last
reference to the user space file was closed. This would be the time that it
is safe to free the file meta data.
A shortcut was made for the "format" file. It's i_private would point to
the "call" entry directly and not point to the file's meta data. This is
because all format files are the same for the same "call", so it was
thought there was no reason to differentiate them. The other files
maintain state (like the "enable", "trigger", etc). But this meant if the
file were to disappear, the "format" file would be unaware of it.
This caused a race that could be trigger via the user_events test (that
would create dynamic events and free them), and running a loop that would
read the user_events format files:
In one console run:
# cd tools/testing/selftests/user_events
# while true; do ./ftrace_test; done
And in another console run:
# cd /sys/kernel/tracing/
# while true; do cat events/user_events/__test_event/format; done 2>/dev/null
With KASAN memory checking, it would trigger a use-after-free bug report
(which was a real bug). This was because the format file was not checking
the file's meta data flag "EVENT_FILE_FL_FREED", so it would access the
event that the file meta data pointed to after the event was freed.
After inspection, there are other locations that were found to not check
the EVENT_FILE_FL_FREED flag when accessing the trace_event_file. Add a
new helper function: event_file_file() that will make sure that the
event_mutex is held, and will return NULL if the trace_event_file has the
EVENT_FILE_FL_FREED flag set. Have the first reference of the struct file
pointer use event_file_file() and check for NULL. Later uses can still use
the event_file_data() helper function if the event_mutex is still held and
was not released since the event_file_file() call.