Debian: >> Debian Linux >> 10.0 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
mm: swap: fix race between free_swap_and_cache() and swapoff()
There was previously a theoretical window where swapoff() could run and
teardown a swap_info_struct while a call to free_swap_and_cache() was
running in another thread. This could cause, amongst other bad
possibilities, swap_page_trans_huge_swapped() (called by
free_swap_and_cache()) to access the freed memory for swap_map.
This is a theoretical problem and I haven't been able to provoke it from a
test case. But there has been agreement based on code review that this is
possible (see link below).
Fix it by using get_swap_device()/put_swap_device(), which will stall
swapoff(). There was an extra check in _swap_info_get() to confirm that
the swap entry was not free. This isn't present in get_swap_device()
because it doesn't make sense in general due to the race between getting
the reference and swapoff. So I've added an equivalent check directly in
free_swap_and_cache().
Details of how to provoke one possible issue (thanks to David Hildenbrand
for deriving this):
--8<-----
__swap_entry_free() might be the last user and result in
"count == SWAP_HAS_CACHE".
swapoff->try_to_unuse() will stop as soon as soon as si->inuse_pages==0.
So the question is: could someone reclaim the folio and turn
si->inuse_pages==0, before we completed swap_page_trans_huge_swapped().
Imagine the following: 2 MiB folio in the swapcache. Only 2 subpages are
still references by swap entries.
Process 1 still references subpage 0 via swap entry.
Process 2 still references subpage 1 via swap entry.
Process 1 quits. Calls free_swap_and_cache().
-> count == SWAP_HAS_CACHE
[then, preempted in the hypervisor etc.]
Process 2 quits. Calls free_swap_and_cache().
-> count == SWAP_HAS_CACHE
Process 2 goes ahead, passes swap_page_trans_huge_swapped(), and calls
__try_to_reclaim_swap().
__try_to_reclaim_swap()->folio_free_swap()->delete_from_swap_cache()->
put_swap_folio()->free_swap_slot()->swapcache_free_entries()->
swap_entry_free()->swap_range_free()->
...
WRITE_ONCE(si->inuse_pages, si->inuse_pages - nr_entries);
What stops swapoff to succeed after process 2 reclaimed the swap cache
but before process1 finished its call to swap_page_trans_huge_swapped()?
--8<-----
CVSS Score
5.5
EPSS Score
0.0
Published
2024-05-01
In the Linux kernel, the following vulnerability has been resolved:
clk: qcom: mmcc-msm8974: fix terminating of frequency table arrays
The frequency table arrays are supposed to be terminated with an
empty element. Add such entry to the end of the arrays where it
is missing in order to avoid possible out-of-bound access when
the table is traversed by functions like qcom_find_freq() or
qcom_find_freq_floor().
Only compile tested.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-05-01
In the Linux kernel, the following vulnerability has been resolved:
clk: qcom: mmcc-apq8084: fix terminating of frequency table arrays
The frequency table arrays are supposed to be terminated with an
empty element. Add such entry to the end of the arrays where it
is missing in order to avoid possible out-of-bound access when
the table is traversed by functions like qcom_find_freq() or
qcom_find_freq_floor().
Only compile tested.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-05-01
In the Linux kernel, the following vulnerability has been resolved:
wireguard: netlink: access device through ctx instead of peer
The previous commit fixed a bug that led to a NULL peer->device being
dereferenced. It's actually easier and faster performance-wise to
instead get the device from ctx->wg. This semantically makes more sense
too, since ctx->wg->peer_allowedips.seq is compared with
ctx->allowedips_seq, basing them both in ctx. This also acts as a
defence in depth provision against freed peers.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-05-01
In the Linux kernel, the following vulnerability has been resolved:
wireguard: netlink: check for dangling peer via is_dead instead of empty list
If all peers are removed via wg_peer_remove_all(), rather than setting
peer_list to empty, the peer is added to a temporary list with a head on
the stack of wg_peer_remove_all(). If a netlink dump is resumed and the
cursored peer is one that has been removed via wg_peer_remove_all(), it
will iterate from that peer and then attempt to dump freed peers.
Fix this by instead checking peer->is_dead, which was explictly created
for this purpose. Also move up the device_update_lock lockdep assertion,
since reading is_dead relies on that.
It can be reproduced by a small script like:
echo "Setting config..."
ip link add dev wg0 type wireguard
wg setconf wg0 /big-config
(
while true; do
echo "Showing config..."
wg showconf wg0 > /dev/null
done
) &
sleep 4
wg setconf wg0 <(printf "[Peer]\nPublicKey=$(wg genkey)\n")
Resulting in:
BUG: KASAN: slab-use-after-free in __lock_acquire+0x182a/0x1b20
Read of size 8 at addr ffff88811956ec70 by task wg/59
CPU: 2 PID: 59 Comm: wg Not tainted 6.8.0-rc2-debug+ #5
Call Trace:
<TASK>
dump_stack_lvl+0x47/0x70
print_address_description.constprop.0+0x2c/0x380
print_report+0xab/0x250
kasan_report+0xba/0xf0
__lock_acquire+0x182a/0x1b20
lock_acquire+0x191/0x4b0
down_read+0x80/0x440
get_peer+0x140/0xcb0
wg_get_device_dump+0x471/0x1130
CVSS Score
7.8
EPSS Score
0.0
Published
2024-05-01
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: prevent kernel bug at submit_bh_wbc()
Fix a bug where nilfs_get_block() returns a successful status when
searching and inserting the specified block both fail inconsistently. If
this inconsistent behavior is not due to a previously fixed bug, then an
unexpected race is occurring, so return a temporary error -EAGAIN instead.
This prevents callers such as __block_write_begin_int() from requesting a
read into a buffer that is not mapped, which would cause the BUG_ON check
for the BH_Mapped flag in submit_bh_wbc() to fail.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-05-01
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix failure to detect DAT corruption in btree and direct mappings
Patch series "nilfs2: fix kernel bug at submit_bh_wbc()".
This resolves a kernel BUG reported by syzbot. Since there are two
flaws involved, I've made each one a separate patch.
The first patch alone resolves the syzbot-reported bug, but I think
both fixes should be sent to stable, so I've tagged them as such.
This patch (of 2):
Syzbot has reported a kernel bug in submit_bh_wbc() when writing file data
to a nilfs2 file system whose metadata is corrupted.
There are two flaws involved in this issue.
The first flaw is that when nilfs_get_block() locates a data block using
btree or direct mapping, if the disk address translation routine
nilfs_dat_translate() fails with internal code -ENOENT due to DAT metadata
corruption, it can be passed back to nilfs_get_block(). This causes
nilfs_get_block() to misidentify an existing block as non-existent,
causing both data block lookup and insertion to fail inconsistently.
The second flaw is that nilfs_get_block() returns a successful status in
this inconsistent state. This causes the caller __block_write_begin_int()
or others to request a read even though the buffer is not mapped,
resulting in a BUG_ON check for the BH_Mapped flag in submit_bh_wbc()
failing.
This fixes the first issue by changing the return value to code -EINVAL
when a conversion using DAT fails with code -ENOENT, avoiding the
conflicting condition that leads to the kernel bug described above. Here,
code -EINVAL indicates that metadata corruption was detected during the
block lookup, which will be properly handled as a file system error and
converted to -EIO when passing through the nilfs2 bmap layer.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-05-01
In the Linux kernel, the following vulnerability has been resolved:
s390/zcrypt: fix reference counting on zcrypt card objects
Tests with hot-plugging crytpo cards on KVM guests with debug
kernel build revealed an use after free for the load field of
the struct zcrypt_card. The reason was an incorrect reference
handling of the zcrypt card object which could lead to a free
of the zcrypt card object while it was still in use.
This is an example of the slab message:
kernel: 0x00000000885a7512-0x00000000885a7513 @offset=1298. First byte 0x68 instead of 0x6b
kernel: Allocated in zcrypt_card_alloc+0x36/0x70 [zcrypt] age=18046 cpu=3 pid=43
kernel: kmalloc_trace+0x3f2/0x470
kernel: zcrypt_card_alloc+0x36/0x70 [zcrypt]
kernel: zcrypt_cex4_card_probe+0x26/0x380 [zcrypt_cex4]
kernel: ap_device_probe+0x15c/0x290
kernel: really_probe+0xd2/0x468
kernel: driver_probe_device+0x40/0xf0
kernel: __device_attach_driver+0xc0/0x140
kernel: bus_for_each_drv+0x8c/0xd0
kernel: __device_attach+0x114/0x198
kernel: bus_probe_device+0xb4/0xc8
kernel: device_add+0x4d2/0x6e0
kernel: ap_scan_adapter+0x3d0/0x7c0
kernel: ap_scan_bus+0x5a/0x3b0
kernel: ap_scan_bus_wq_callback+0x40/0x60
kernel: process_one_work+0x26e/0x620
kernel: worker_thread+0x21c/0x440
kernel: Freed in zcrypt_card_put+0x54/0x80 [zcrypt] age=9024 cpu=3 pid=43
kernel: kfree+0x37e/0x418
kernel: zcrypt_card_put+0x54/0x80 [zcrypt]
kernel: ap_device_remove+0x4c/0xe0
kernel: device_release_driver_internal+0x1c4/0x270
kernel: bus_remove_device+0x100/0x188
kernel: device_del+0x164/0x3c0
kernel: device_unregister+0x30/0x90
kernel: ap_scan_adapter+0xc8/0x7c0
kernel: ap_scan_bus+0x5a/0x3b0
kernel: ap_scan_bus_wq_callback+0x40/0x60
kernel: process_one_work+0x26e/0x620
kernel: worker_thread+0x21c/0x440
kernel: kthread+0x150/0x168
kernel: __ret_from_fork+0x3c/0x58
kernel: ret_from_fork+0xa/0x30
kernel: Slab 0x00000372022169c0 objects=20 used=18 fp=0x00000000885a7c88 flags=0x3ffff00000000a00(workingset|slab|node=0|zone=1|lastcpupid=0x1ffff)
kernel: Object 0x00000000885a74b8 @offset=1208 fp=0x00000000885a7c88
kernel: Redzone 00000000885a74b0: bb bb bb bb bb bb bb bb ........
kernel: Object 00000000885a74b8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
kernel: Object 00000000885a74c8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
kernel: Object 00000000885a74d8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
kernel: Object 00000000885a74e8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
kernel: Object 00000000885a74f8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
kernel: Object 00000000885a7508: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 68 4b 6b 6b 6b a5 kkkkkkkkkkhKkkk.
kernel: Redzone 00000000885a7518: bb bb bb bb bb bb bb bb ........
kernel: Padding 00000000885a756c: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZ
kernel: CPU: 0 PID: 387 Comm: systemd-udevd Not tainted 6.8.0-HF #2
kernel: Hardware name: IBM 3931 A01 704 (KVM/Linux)
kernel: Call Trace:
kernel: [<00000000ca5ab5b8>] dump_stack_lvl+0x90/0x120
kernel: [<00000000c99d78bc>] check_bytes_and_report+0x114/0x140
kernel: [<00000000c99d53cc>] check_object+0x334/0x3f8
kernel: [<00000000c99d820c>] alloc_debug_processing+0xc4/0x1f8
kernel: [<00000000c99d852e>] get_partial_node.part.0+0x1ee/0x3e0
kernel: [<00000000c99d94ec>] ___slab_alloc+0xaf4/0x13c8
kernel: [<00000000c99d9e38>] __slab_alloc.constprop.0+0x78/0xb8
kernel: [<00000000c99dc8dc>] __kmalloc+0x434/0x590
kernel: [<00000000c9b4c0ce>] ext4_htree_store_dirent+0x4e/0x1c0
kernel: [<00000000c9b908a2>] htree_dirblock_to_tree+0x17a/0x3f0
kernel:
---truncated---
CVSS Score
7.8
EPSS Score
0.0
Published
2024-05-01
In the Linux kernel, the following vulnerability has been resolved:
scsi: core: Fix unremoved procfs host directory regression
Commit fc663711b944 ("scsi: core: Remove the /proc/scsi/${proc_name}
directory earlier") fixed a bug related to modules loading/unloading, by
adding a call to scsi_proc_hostdir_rm() on scsi_remove_host(). But that led
to a potential duplicate call to the hostdir_rm() routine, since it's also
called from scsi_host_dev_release(). That triggered a regression report,
which was then fixed by commit be03df3d4bfe ("scsi: core: Fix a procfs host
directory removal regression"). The fix just dropped the hostdir_rm() call
from dev_release().
But it happens that this proc directory is created on scsi_host_alloc(),
and that function "pairs" with scsi_host_dev_release(), while
scsi_remove_host() pairs with scsi_add_host(). In other words, it seems the
reason for removing the proc directory on dev_release() was meant to cover
cases in which a SCSI host structure was allocated, but the call to
scsi_add_host() didn't happen. And that pattern happens to exist in some
error paths, for example.
Syzkaller causes that by using USB raw gadget device, error'ing on
usb-storage driver, at usb_stor_probe2(). By checking that path, we can see
that the BadDevice label leads to a scsi_host_put() after a SCSI host
allocation, but there's no call to scsi_add_host() in such path. That leads
to messages like this in dmesg (and a leak of the SCSI host proc
structure):
usb-storage 4-1:87.51: USB Mass Storage device detected
proc_dir_entry 'scsi/usb-storage' already registered
WARNING: CPU: 1 PID: 3519 at fs/proc/generic.c:377 proc_register+0x347/0x4e0 fs/proc/generic.c:376
The proper fix seems to still call scsi_proc_hostdir_rm() on dev_release(),
but guard that with the state check for SHOST_CREATED; there is even a
comment in scsi_host_dev_release() detailing that: such conditional is
meant for cases where the SCSI host was allocated but there was no calls to
{add,remove}_host(), like the usb-storage case.
This is what we propose here and with that, the error path of usb-storage
does not trigger the warning anymore.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-05-01
In the Linux kernel, the following vulnerability has been resolved:
drm/i915/gt: Reset queue_priority_hint on parking
Originally, with strict in order execution, we could complete execution
only when the queue was empty. Preempt-to-busy allows replacement of an
active request that may complete before the preemption is processed by
HW. If that happens, the request is retired from the queue, but the
queue_priority_hint remains set, preventing direct submission until
after the next CS interrupt is processed.
This preempt-to-busy race can be triggered by the heartbeat, which will
also act as the power-management barrier and upon completion allow us to
idle the HW. We may process the completion of the heartbeat, and begin
parking the engine before the CS event that restores the
queue_priority_hint, causing us to fail the assertion that it is MIN.
<3>[ 166.210729] __engine_park:283 GEM_BUG_ON(engine->sched_engine->queue_priority_hint != (-((int)(~0U >> 1)) - 1))
<0>[ 166.210781] Dumping ftrace buffer:
<0>[ 166.210795] ---------------------------------
...
<0>[ 167.302811] drm_fdin-1097 2..s1. 165741070us : trace_ports: 0000:00:02.0 rcs0: promote { ccid:20 1217:2 prio 0 }
<0>[ 167.302861] drm_fdin-1097 2d.s2. 165741072us : execlists_submission_tasklet: 0000:00:02.0 rcs0: preempting last=1217:2, prio=0, hint=2147483646
<0>[ 167.302928] drm_fdin-1097 2d.s2. 165741072us : __i915_request_unsubmit: 0000:00:02.0 rcs0: fence 1217:2, current 0
<0>[ 167.302992] drm_fdin-1097 2d.s2. 165741073us : __i915_request_submit: 0000:00:02.0 rcs0: fence 3:4660, current 4659
<0>[ 167.303044] drm_fdin-1097 2d.s1. 165741076us : execlists_submission_tasklet: 0000:00:02.0 rcs0: context:3 schedule-in, ccid:40
<0>[ 167.303095] drm_fdin-1097 2d.s1. 165741077us : trace_ports: 0000:00:02.0 rcs0: submit { ccid:40 3:4660* prio 2147483646 }
<0>[ 167.303159] kworker/-89 11..... 165741139us : i915_request_retire.part.0: 0000:00:02.0 rcs0: fence c90:2, current 2
<0>[ 167.303208] kworker/-89 11..... 165741148us : __intel_context_do_unpin: 0000:00:02.0 rcs0: context:c90 unpin
<0>[ 167.303272] kworker/-89 11..... 165741159us : i915_request_retire.part.0: 0000:00:02.0 rcs0: fence 1217:2, current 2
<0>[ 167.303321] kworker/-89 11..... 165741166us : __intel_context_do_unpin: 0000:00:02.0 rcs0: context:1217 unpin
<0>[ 167.303384] kworker/-89 11..... 165741170us : i915_request_retire.part.0: 0000:00:02.0 rcs0: fence 3:4660, current 4660
<0>[ 167.303434] kworker/-89 11d..1. 165741172us : __intel_context_retire: 0000:00:02.0 rcs0: context:1216 retire runtime: { total:56028ns, avg:56028ns }
<0>[ 167.303484] kworker/-89 11..... 165741198us : __engine_park: 0000:00:02.0 rcs0: parked
<0>[ 167.303534] <idle>-0 5d.H3. 165741207us : execlists_irq_handler: 0000:00:02.0 rcs0: semaphore yield: 00000040
<0>[ 167.303583] kworker/-89 11..... 165741397us : __intel_context_retire: 0000:00:02.0 rcs0: context:1217 retire runtime: { total:325575ns, avg:0ns }
<0>[ 167.303756] kworker/-89 11..... 165741777us : __intel_context_retire: 0000:00:02.0 rcs0: context:c90 retire runtime: { total:0ns, avg:0ns }
<0>[ 167.303806] kworker/-89 11..... 165742017us : __engine_park: __engine_park:283 GEM_BUG_ON(engine->sched_engine->queue_priority_hint != (-((int)(~0U >> 1)) - 1))
<0>[ 167.303811] ---------------------------------
<4>[ 167.304722] ------------[ cut here ]------------
<2>[ 167.304725] kernel BUG at drivers/gpu/drm/i915/gt/intel_engine_pm.c:283!
<4>[ 167.304731] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
<4>[ 167.304734] CPU: 11 PID: 89 Comm: kworker/11:1 Tainted: G W 6.8.0-rc2-CI_DRM_14193-gc655e0fd2804+ #1
<4>[ 167.304736] Hardware name: Intel Corporation Rocket Lake Client Platform/RocketLake S UDIMM 6L RVP, BIOS RKLSFWI1.R00.3173.A03.2204210138 04/21/2022
<4>[ 167.304738] Workqueue: i915-unordered retire_work_handler [i915]
<4>[ 16
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2024-05-01