| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| A flaw was found in QEMU. An assertion failure was present in the usb_ep_get() function in hw/net/core.c when trying to get the USB endpoint from a USB device. This flaw may allow a malicious unprivileged guest user to crash the QEMU process on the host and cause a denial of service condition. |
| A flaw was found in D-Bus. With a privileged Monitoring client attached (for example dbus-monitor or busctl monitor), an unprivileged local user can cause dbus-daemon to abort if a driver-originated broadcast such as NameOwnerChanged or ActivatableServicesChanged cannot be delivered to a recipient (for example due to a deny rule or an exceeded outgoing message queue). Driver broadcasts still use serial 0; when delivery fails, composing the monitor error reply asserts reply_serial != 0 and aborts the daemon. This is an incomplete fix for CVE-2023-34969, which only assigned serials for driver messages sent to a single recipient. On the well-known system bus this is a denial of service. |
| A flaw was found in `cockpit-ws`. This vulnerability allows a remote, unauthenticated attacker to cause a Denial of Service (DoS) by sending a specially crafted request. When the `WebService.UrlRoot` is configured and a request is made to the exact URL-root prefix without a trailing slash, `cockpit-ws` can terminate unexpectedly. This issue leads to the unavailability of the Cockpit web service. |
| A flaw was found in nfs-utils. The fsidd daemon improperly handles input received over its local domain socket by relying on program assertions to verify command arguments. A local user can exploit this vulnerability by sending a malformed request lacking the required arguments to trigger an assertion failure. This causes the daemon to crash, resulting in a Denial of Service (DoS) for filesystem identifier lookup services until restarted. |
| A flaw was found in libsoup. When a client sends an HTTP/2 request body from a non-pollable input stream, the library can buffer more data than the current flow-control window later allows. A malicious HTTP/2 server can shrink SETTINGS_INITIAL_WINDOW_SIZE while that buffered read is still in progress. The client then copies the full buffer into a smaller DATA callback without a runtime bounds check, which can abort the process or fail the HTTP/2 session. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: replace BUG_ON with proper error handling in ext4_read_inline_folio
Replace BUG_ON() with proper error handling when inline data size
exceeds PAGE_SIZE. This prevents kernel panic and allows the system to
continue running while properly reporting the filesystem corruption.
The error is logged via ext4_error_inode(), the buffer head is released
to prevent memory leak, and -EFSCORRUPTED is returned to indicate
filesystem corruption. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: avoid overflows in ip6_datagram_send_ctl()
Yiming Qian reported :
<quote>
I believe I found a locally triggerable kernel bug in the IPv6 sendmsg
ancillary-data path that can panic the kernel via `skb_under_panic()`
(local DoS).
The core issue is a mismatch between:
- a 16-bit length accumulator (`struct ipv6_txoptions::opt_flen`, type
`__u16`) and
- a pointer to the *last* provided destination-options header (`opt->dst1opt`)
when multiple `IPV6_DSTOPTS` control messages (cmsgs) are provided.
- `include/net/ipv6.h`:
- `struct ipv6_txoptions::opt_flen` is `__u16` (wrap possible).
(lines 291-307, especially 298)
- `net/ipv6/datagram.c:ip6_datagram_send_ctl()`:
- Accepts repeated `IPV6_DSTOPTS` and accumulates into `opt_flen`
without rejecting duplicates. (lines 909-933)
- `net/ipv6/ip6_output.c:__ip6_append_data()`:
- Uses `opt->opt_flen + opt->opt_nflen` to compute header
sizes/headroom decisions. (lines 1448-1466, especially 1463-1465)
- `net/ipv6/ip6_output.c:__ip6_make_skb()`:
- Calls `ipv6_push_frag_opts()` if `opt->opt_flen` is non-zero.
(lines 1930-1934)
- `net/ipv6/exthdrs.c:ipv6_push_frag_opts()` / `ipv6_push_exthdr()`:
- Push size comes from `ipv6_optlen(opt->dst1opt)` (based on the
pointed-to header). (lines 1179-1185 and 1206-1211)
1. `opt_flen` is a 16-bit accumulator:
- `include/net/ipv6.h:298` defines `__u16 opt_flen; /* after fragment hdr */`.
2. `ip6_datagram_send_ctl()` accepts *repeated* `IPV6_DSTOPTS` cmsgs
and increments `opt_flen` each time:
- In `net/ipv6/datagram.c:909-933`, for `IPV6_DSTOPTS`:
- It computes `len = ((hdr->hdrlen + 1) << 3);`
- It checks `CAP_NET_RAW` using `ns_capable(net->user_ns,
CAP_NET_RAW)`. (line 922)
- Then it does:
- `opt->opt_flen += len;` (line 927)
- `opt->dst1opt = hdr;` (line 928)
There is no duplicate rejection here (unlike the legacy
`IPV6_2292DSTOPTS` path which rejects duplicates at
`net/ipv6/datagram.c:901-904`).
If enough large `IPV6_DSTOPTS` cmsgs are provided, `opt_flen` wraps
while `dst1opt` still points to a large (2048-byte)
destination-options header.
In the attached PoC (`poc.c`):
- 32 cmsgs with `hdrlen=255` => `len = (255+1)*8 = 2048`
- 1 cmsg with `hdrlen=0` => `len = 8`
- Total increment: `32*2048 + 8 = 65544`, so `(__u16)opt_flen == 8`
- The last cmsg is 2048 bytes, so `dst1opt` points to a 2048-byte header.
3. The transmit path sizes headers using the wrapped `opt_flen`:
- In `net/ipv6/ip6_output.c:1463-1465`:
- `headersize = sizeof(struct ipv6hdr) + (opt ? opt->opt_flen +
opt->opt_nflen : 0) + ...;`
With wrapped `opt_flen`, `headersize`/headroom decisions underestimate
what will be pushed later.
4. When building the final skb, the actual push length comes from
`dst1opt` and is not limited by wrapped `opt_flen`:
- In `net/ipv6/ip6_output.c:1930-1934`:
- `if (opt->opt_flen) proto = ipv6_push_frag_opts(skb, opt, proto);`
- In `net/ipv6/exthdrs.c:1206-1211`, `ipv6_push_frag_opts()` pushes
`dst1opt` via `ipv6_push_exthdr()`.
- In `net/ipv6/exthdrs.c:1179-1184`, `ipv6_push_exthdr()` does:
- `skb_push(skb, ipv6_optlen(opt));`
- `memcpy(h, opt, ipv6_optlen(opt));`
With insufficient headroom, `skb_push()` underflows and triggers
`skb_under_panic()` -> `BUG()`:
- `net/core/skbuff.c:2669-2675` (`skb_push()` calls `skb_under_panic()`)
- `net/core/skbuff.c:207-214` (`skb_panic()` ends in `BUG()`)
- The `IPV6_DSTOPTS` cmsg path requires `CAP_NET_RAW` in the target
netns user namespace (`ns_capable(net->user_ns, CAP_NET_RAW)`).
- Root (or any task with `CAP_NET_RAW`) can trigger this without user
namespaces.
- An unprivileged `uid=1000` user can trigger this if unprivileged
user namespaces are enabled and it can create a userns+netns to obtain
namespaced `CAP_NET_RAW` (the attached PoC does this).
- Local denial of service: kernel BUG/panic (system crash).
-
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/io-pgtable-arm: fix size_t signedness bug in unmap path
__arm_lpae_unmap() returns size_t but was returning -ENOENT (negative
error code) when encountering an unmapped PTE. Since size_t is unsigned,
-ENOENT (typically -2) becomes a huge positive value (0xFFFFFFFFFFFFFFFE
on 64-bit systems).
This corrupted value propagates through the call chain:
__arm_lpae_unmap() returns -ENOENT as size_t
-> arm_lpae_unmap_pages() returns it
-> __iommu_unmap() adds it to iova address
-> iommu_pgsize() triggers BUG_ON due to corrupted iova
This can cause IOVA address overflow in __iommu_unmap() loop and
trigger BUG_ON in iommu_pgsize() from invalid address alignment.
Fix by returning 0 instead of -ENOENT. The WARN_ON already signals
the error condition, and returning 0 (meaning "nothing unmapped")
is the correct semantic for size_t return type. This matches the
behavior of other io-pgtable implementations (io-pgtable-arm-v7s,
io-pgtable-dart) which return 0 on error conditions. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: dwc3: Remove WARN_ON for device endpoint command timeouts
This commit addresses a rarely observed endpoint command timeout
which causes kernel panic due to warn when 'panic_on_warn' is enabled
and unnecessary call trace prints when 'panic_on_warn' is disabled.
It is seen during fast software-controlled connect/disconnect testcases.
The following is one such endpoint command timeout that we observed:
1. Connect
=======
->dwc3_thread_interrupt
->dwc3_ep0_interrupt
->configfs_composite_setup
->composite_setup
->usb_ep_queue
->dwc3_gadget_ep0_queue
->__dwc3_gadget_ep0_queue
->__dwc3_ep0_do_control_data
->dwc3_send_gadget_ep_cmd
2. Disconnect
==========
->dwc3_thread_interrupt
->dwc3_gadget_disconnect_interrupt
->dwc3_ep0_reset_state
->dwc3_ep0_end_control_data
->dwc3_send_gadget_ep_cmd
In the issue scenario, in Exynos platforms, we observed that control
transfers for the previous connect have not yet been completed and end
transfer command sent as a part of the disconnect sequence and
processing of USB_ENDPOINT_HALT feature request from the host timeout.
This maybe an expected scenario since the controller is processing EP
commands sent as a part of the previous connect. It maybe better to
remove WARN_ON in all places where device endpoint commands are sent to
avoid unnecessary kernel panic due to warn. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: do not BUG when INLINE_DATA_FL lacks system.data xattr
A syzbot fuzzed image triggered a BUG_ON in ext4_update_inline_data()
when an inode had the INLINE_DATA_FL flag set but was missing the
system.data extended attribute.
Since this can happen due to a maiciouly fuzzed file system, we
shouldn't BUG, but rather, report it as a corrupted file system.
Add similar replacements of BUG_ON with EXT4_ERROR_INODE() ii
ext4_create_inline_data() and ext4_inline_data_truncate(). |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: fix WARN_ON for monitor mode on some devices
On devices without WANT_MONITOR_VIF (and probably without
channel context support) we get a WARN_ON for changing the
per-link setting of a monitor interface.
Since we already skip AP_VLAN interfaces and MONITOR with
WANT_MONITOR_VIF and/or NO_VIRTUAL_MONITOR should update
the settings, catch this in the link change code instead
of the warning. |
| In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix bug due to prealloc collision
When userspace is using AF_RXRPC to provide a server, it has to preallocate
incoming calls and assign to them call IDs that will be used to thread
related recvmsg() and sendmsg() together. The preallocated call IDs will
automatically be attached to calls as they come in until the pool is empty.
To the kernel, the call IDs are just arbitrary numbers, but userspace can
use the call ID to hold a pointer to prepared structs. In any case, the
user isn't permitted to create two calls with the same call ID (call IDs
become available again when the call ends) and EBADSLT should result from
sendmsg() if an attempt is made to preallocate a call with an in-use call
ID.
However, the cleanup in the error handling will trigger both assertions in
rxrpc_cleanup_call() because the call isn't marked complete and isn't
marked as having been released.
Fix this by setting the call state in rxrpc_service_prealloc_one() and then
marking it as being released before calling the cleanup function. |
| A denial of service vulnerability was found in GStreamer's AV1 codec parser in gst-plugins-bad. The gst_av1_parser_parse_tile_list_obu() function passes a byte count to a bit-reader API that expects a bit count, causing parser desynchronization. A remote attacker could trick a user into opening a specially crafted AV1 media file, triggering an assertion abort and causing the application to crash. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix WARN() in get_bpf_raw_tp_regs
syzkaller reported an issue:
WARNING: CPU: 3 PID: 5971 at kernel/trace/bpf_trace.c:1861 get_bpf_raw_tp_regs+0xa4/0x100 kernel/trace/bpf_trace.c:1861
Modules linked in:
CPU: 3 UID: 0 PID: 5971 Comm: syz-executor205 Not tainted 6.15.0-rc5-syzkaller-00038-g707df3375124 #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:get_bpf_raw_tp_regs+0xa4/0x100 kernel/trace/bpf_trace.c:1861
RSP: 0018:ffffc90003636fa8 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffffffff81c6bc4c
RDX: ffff888032efc880 RSI: ffffffff81c6bc83 RDI: 0000000000000005
RBP: ffff88806a730860 R08: 0000000000000005 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000000 R12: 0000000000000004
R13: 0000000000000001 R14: ffffc90003637008 R15: 0000000000000900
FS: 0000000000000000(0000) GS:ffff8880d6cdf000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7baee09130 CR3: 0000000029f5a000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1934 [inline]
bpf_get_stack_raw_tp+0x24/0x160 kernel/trace/bpf_trace.c:1931
bpf_prog_ec3b2eefa702d8d3+0x43/0x47
bpf_dispatcher_nop_func include/linux/bpf.h:1316 [inline]
__bpf_prog_run include/linux/filter.h:718 [inline]
bpf_prog_run include/linux/filter.h:725 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2363 [inline]
bpf_trace_run3+0x23f/0x5a0 kernel/trace/bpf_trace.c:2405
__bpf_trace_mmap_lock_acquire_returned+0xfc/0x140 include/trace/events/mmap_lock.h:47
__traceiter_mmap_lock_acquire_returned+0x79/0xc0 include/trace/events/mmap_lock.h:47
__do_trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:47 [inline]
trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:47 [inline]
__mmap_lock_do_trace_acquire_returned+0x138/0x1f0 mm/mmap_lock.c:35
__mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline]
mmap_read_trylock include/linux/mmap_lock.h:204 [inline]
stack_map_get_build_id_offset+0x535/0x6f0 kernel/bpf/stackmap.c:157
__bpf_get_stack+0x307/0xa10 kernel/bpf/stackmap.c:483
____bpf_get_stack kernel/bpf/stackmap.c:499 [inline]
bpf_get_stack+0x32/0x40 kernel/bpf/stackmap.c:496
____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1941 [inline]
bpf_get_stack_raw_tp+0x124/0x160 kernel/trace/bpf_trace.c:1931
bpf_prog_ec3b2eefa702d8d3+0x43/0x47
Tracepoint like trace_mmap_lock_acquire_returned may cause nested call
as the corner case show above, which will be resolved with more general
method in the future. As a result, WARN_ON_ONCE will be triggered. As
Alexei suggested, remove the WARN_ON_ONCE first. |
| In the Linux kernel, the following vulnerability has been resolved:
dm cache: prevent BUG_ON by blocking retries on failed device resumes
A cache device failing to resume due to mapping errors should not be
retried, as the failure leaves a partially initialized policy object.
Repeating the resume operation risks triggering BUG_ON when reloading
cache mappings into the incomplete policy object.
Reproduce steps:
1. create a cache metadata consisting of 512 or more cache blocks,
with some mappings stored in the first array block of the mapping
array. Here we use cache_restore v1.0 to build the metadata.
cat <<EOF >> cmeta.xml
<superblock uuid="" block_size="128" nr_cache_blocks="512" \
policy="smq" hint_width="4">
<mappings>
<mapping cache_block="0" origin_block="0" dirty="false"/>
</mappings>
</superblock>
EOF
dmsetup create cmeta --table "0 8192 linear /dev/sdc 0"
cache_restore -i cmeta.xml -o /dev/mapper/cmeta --metadata-version=2
dmsetup remove cmeta
2. wipe the second array block of the mapping array to simulate
data degradations.
mapping_root=$(dd if=/dev/sdc bs=1c count=8 skip=192 \
2>/dev/null | hexdump -e '1/8 "%u\n"')
ablock=$(dd if=/dev/sdc bs=1c count=8 skip=$((4096*mapping_root+2056)) \
2>/dev/null | hexdump -e '1/8 "%u\n"')
dd if=/dev/zero of=/dev/sdc bs=4k count=1 seek=$ablock
3. try bringing up the cache device. The resume is expected to fail
due to the broken array block.
dmsetup create cmeta --table "0 8192 linear /dev/sdc 0"
dmsetup create cdata --table "0 65536 linear /dev/sdc 8192"
dmsetup create corig --table "0 524288 linear /dev/sdc 262144"
dmsetup create cache --notable
dmsetup load cache --table "0 524288 cache /dev/mapper/cmeta \
/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0"
dmsetup resume cache
4. try resuming the cache again. An unexpected BUG_ON is triggered
while loading cache mappings.
dmsetup resume cache
Kernel logs:
(snip)
------------[ cut here ]------------
kernel BUG at drivers/md/dm-cache-policy-smq.c:752!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 332 Comm: dmsetup Not tainted 6.13.4 #3
RIP: 0010:smq_load_mapping+0x3e5/0x570
Fix by disallowing resume operations for devices that failed the
initial attempt. |
| In the Linux kernel, the following vulnerability has been resolved:
perf/core: Fix WARN_ON(!ctx) in __free_event() for partial init
Move the get_ctx(child_ctx) call and the child_event->ctx assignment to
occur immediately after the child event is allocated. Ensure that
child_event->ctx is non-NULL before any subsequent error path within
inherit_event calls free_event(), satisfying the assumptions of the
cleanup code.
Details:
There's no clear Fixes tag, because this bug is a side-effect of
multiple interacting commits over time (up to 15 years old), not
a single regression.
The code initially incremented refcount then assigned context
immediately after the child_event was created. Later, an early
validity check for child_event was added before the
refcount/assignment. Even later, a WARN_ON_ONCE() cleanup check was
added, assuming event->ctx is valid if the pmu_ctx is valid.
The problem is that the WARN_ON_ONCE() could trigger after the initial
check passed but before child_event->ctx was assigned, violating its
precondition. The solution is to assign child_event->ctx right after
its initial validation. This ensures the context exists for any
subsequent checks or cleanup routines, resolving the WARN_ON_ONCE().
To resolve it, defer the refcount update and child_event->ctx assignment
directly after child_event->pmu_ctx is set but before checking if the
parent event is orphaned. The cleanup routine depends on
event->pmu_ctx being non-NULL before it verifies event->ctx is
non-NULL. This also maintains the author's original intent of passing
in child_ctx to find_get_pmu_context before its refcount/assignment.
[ mingo: Expanded the changelog from another email by Gabriel Shahrouzi. ] |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: ymfpci: Fix BUG_ON in probe function
The snd_dma_buffer.bytes field now contains the aligned size, which this
snd_BUG_ON() did not account for, resulting in the following:
[ 9.625915] ------------[ cut here ]------------
[ 9.633440] WARNING: CPU: 0 PID: 126 at sound/pci/ymfpci/ymfpci_main.c:2168 snd_ymfpci_create+0x681/0x698 [snd_ymfpci]
[ 9.648926] Modules linked in: snd_ymfpci(+) snd_intel_dspcfg kvm(+) snd_intel_sdw_acpi snd_ac97_codec snd_mpu401_uart snd_opl3_lib irqbypass snd_hda_codec gameport snd_rawmidi crct10dif_pclmul crc32_pclmul cfg80211 snd_hda_core polyval_clmulni polyval_generic gf128mul snd_seq_device ghash_clmulni_intel snd_hwdep ac97_bus sha512_ssse3 rfkill snd_pcm aesni_intel tg3 snd_timer crypto_simd snd mxm_wmi libphy cryptd k10temp fam15h_power pcspkr soundcore sp5100_tco wmi acpi_cpufreq mac_hid dm_multipath sg loop fuse dm_mod bpf_preload ip_tables x_tables ext4 crc32c_generic crc16 mbcache jbd2 sr_mod cdrom ata_generic pata_acpi firewire_ohci crc32c_intel firewire_core xhci_pci crc_itu_t pata_via xhci_pci_renesas floppy
[ 9.711849] CPU: 0 PID: 126 Comm: kworker/0:2 Not tainted 6.1.21-1-lts #1 08d2e5ece03136efa7c6aeea9a9c40916b1bd8da
[ 9.722200] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./990FX Extreme4, BIOS P2.70 06/05/2014
[ 9.732204] Workqueue: events work_for_cpu_fn
[ 9.736580] RIP: 0010:snd_ymfpci_create+0x681/0x698 [snd_ymfpci]
[ 9.742594] Code: 8c c0 4c 89 e2 48 89 df 48 c7 c6 92 c6 8c c0 e8 15 d0 e9 ff 48 83 c4 08 44 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f e9 d3 7a 33 e3 <0f> 0b e9 cb fd ff ff 41 bd fb ff ff ff eb db 41 bd f4 ff ff ff eb
[ 9.761358] RSP: 0018:ffffab64804e7da0 EFLAGS: 00010287
[ 9.766594] RAX: ffff8fa2df06c400 RBX: ffff8fa3073a8000 RCX: ffff8fa303fbc4a8
[ 9.773734] RDX: ffff8fa2df06d000 RSI: 0000000000000010 RDI: 0000000000000020
[ 9.780876] RBP: ffff8fa300b5d0d0 R08: ffff8fa3073a8e50 R09: 00000000df06bf00
[ 9.788018] R10: ffff8fa2df06bf00 R11: 00000000df068200 R12: ffff8fa3073a8918
[ 9.795159] R13: 0000000000000000 R14: 0000000000000080 R15: ffff8fa2df068200
[ 9.802317] FS: 0000000000000000(0000) GS:ffff8fa9fec00000(0000) knlGS:0000000000000000
[ 9.810414] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9.816158] CR2: 000055febaf66500 CR3: 0000000101a2e000 CR4: 00000000000406f0
[ 9.823301] Call Trace:
[ 9.825747] <TASK>
[ 9.827889] snd_card_ymfpci_probe+0x194/0x950 [snd_ymfpci b78a5fe64b5663a6390a909c67808567e3e73615]
[ 9.837030] ? finish_task_switch.isra.0+0x90/0x2d0
[ 9.841918] local_pci_probe+0x45/0x80
[ 9.845680] work_for_cpu_fn+0x1a/0x30
[ 9.849431] process_one_work+0x1c7/0x380
[ 9.853464] worker_thread+0x1af/0x390
[ 9.857225] ? rescuer_thread+0x3b0/0x3b0
[ 9.861254] kthread+0xde/0x110
[ 9.864414] ? kthread_complete_and_exit+0x20/0x20
[ 9.869210] ret_from_fork+0x22/0x30
[ 9.872792] </TASK>
[ 9.874985] ---[ end trace 0000000000000000 ]--- |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: remove a BUG_ON in ext4_mb_release_group_pa()
If a malicious fuzzer overwrites the ext4 superblock while it is
mounted such that the s_first_data_block is set to a very large
number, the calculation of the block group can underflow, and trigger
a BUG_ON check. Change this to be an ext4_warning so that we don't
crash the kernel. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: fix BUG_ON() when directory entry has invalid rec_len
The rec_len field in the directory entry has to be a multiple of 4. A
corrupted filesystem image can be used to hit a BUG() in
ext4_rec_len_to_disk(), called from make_indexed_dir().
------------[ cut here ]------------
kernel BUG at fs/ext4/ext4.h:2413!
...
RIP: 0010:make_indexed_dir+0x53f/0x5f0
...
Call Trace:
<TASK>
? add_dirent_to_buf+0x1b2/0x200
ext4_add_entry+0x36e/0x480
ext4_add_nondir+0x2b/0xc0
ext4_create+0x163/0x200
path_openat+0x635/0xe90
do_filp_open+0xb4/0x160
? __create_object.isra.0+0x1de/0x3b0
? _raw_spin_unlock+0x12/0x30
do_sys_openat2+0x91/0x150
__x64_sys_open+0x6c/0xa0
do_syscall_64+0x3c/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
The fix simply adds a call to ext4_check_dir_entry() to validate the
directory entry, returning -EFSCORRUPTED if the entry is invalid. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: don't BUG if someone dirty pages without asking ext4 first
[un]pin_user_pages_remote is dirtying pages without properly warning
the file system in advance. A related race was noted by Jan Kara in
2018[1]; however, more recently instead of it being a very hard-to-hit
race, it could be reliably triggered by process_vm_writev(2) which was
discovered by Syzbot[2].
This is technically a bug in mm/gup.c, but arguably ext4 is fragile in
that if some other kernel subsystem dirty pages without properly
notifying the file system using page_mkwrite(), ext4 will BUG, while
other file systems will not BUG (although data will still be lost).
So instead of crashing with a BUG, issue a warning (since there may be
potential data loss) and just mark the page as clean to avoid
unprivileged denial of service attacks until the problem can be
properly fixed. More discussion and background can be found in the
thread starting at [2].
[1] https://lore.kernel.org/linux-mm/20180103100430.GE4911@quack2.suse.cz
[2] https://lore.kernel.org/r/Yg0m6IjcNmfaSokM@google.com |
