Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
virt: sev-guest: Do not use host-controlled page order in cleanup path
When issuing an extended guest request (SVM_VMGEXIT_EXT_GUEST_REQUEST),
get_ext_report() allocates a buffer to retrieve a certificate blob from the
host, keeping track of its size in report_req->certs_len.
However, the host may return SNP_GUEST_VMM_ERR_INVALID_LEN, indicating
an invalid buffer size, as well as the expected length of such buffer.
get_ext_report() subsequently updates report_req->certs_len with the
host-controlled value, and cleans up the buffer by computing a page order
from such value. This is incorrect, as the host-provided length may not
match the page order of the original allocation, potentially resulting
in corruption in the page allocator.
Fix this by using alloc_pages_exact() instead, and reusing @npages to
compute the size passed to free_pages_exact(). For consistency, also
use @npages to compute the size when allocating the pages, even though
this last change has no functional effect.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
ceph: put folios not suitable for writeback
The batch holds references to the folios (see `filemap_get_folios`,
`folio_batch_release`), so we need to `folio_put` the folios we remove.
Tested on v6.18.
CVSS Score
7.5
EPSS Score
0.004
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
ceph: fix BUG_ON in __ceph_build_xattrs_blob() due to stale blob size
The generic/642 test-case can reproduce the kernel crash:
[40243.605254] ------------[ cut here ]------------
[40243.605956] kernel BUG at fs/ceph/xattr.c:918!
[40243.607142] Oops: invalid opcode: 0000 [#1] SMP PTI
[40243.608067] CPU: 7 UID: 0 PID: 498762 Comm: kworker/7:1 Not tainted 7.0.0-rc7+ #3 PREEMPT(full)
[40243.609700] Hardware name: QEMU Ubuntu 25.10 PC v2 (i440FX + PIIX, + 10.1 machine, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[40243.611820] Workqueue: ceph-msgr ceph_con_workfn
[40243.612715] RIP: 0010:__ceph_build_xattrs_blob+0x1b8/0x1e0
[40243.613731] Code: 0f 84 82 fe ff ff e9 cf 8e 56 ff 48 8d 65 e8 31 c0 5b 41 5c 41 5d 5d 31 d2 31 c9 31 f6 31 ff 45 31 c0 45 31 c9 c3 cc cc cc cc <0f> 0b 4c 8b 62 08 41 8b 85 24 07 00 00 49 83 c4 04 41 89 44 24 fc
[40243.616888] RSP: 0018:ffffcc80c4d4b688 EFLAGS: 00010287
[40243.617773] RAX: 0000000000010026 RBX: 0000000000000001 RCX: 0000000000000000
[40243.618928] RDX: ffff8a773798dee0 RSI: 0000000000000000 RDI: 0000000000000000
[40243.620158] RBP: ffffcc80c4d4b6a0 R08: 0000000000000000 R09: 0000000000000000
[40243.621573] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8a75f3b58000
[40243.622907] R13: ffff8a75f3b58000 R14: 0000000000000080 R15: 000000000000bffd
[40243.624054] FS: 0000000000000000(0000) GS:ffff8a787d1b4000(0000) knlGS:0000000000000000
[40243.625331] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[40243.626269] CR2: 000072f390b623c0 CR3: 000000011c02a003 CR4: 0000000000372ef0
[40243.627408] Call Trace:
[40243.627839] <TASK>
[40243.628188] __prep_cap+0x3fd/0x4a0
[40243.628789] ? do_raw_spin_unlock+0x4e/0xe0
[40243.629474] ceph_check_caps+0x46a/0xc80
[40243.630094] ? __lock_acquire+0x4a2/0x2650
[40243.630773] ? find_held_lock+0x31/0x90
[40243.631347] ? handle_cap_grant+0x79f/0x1060
[40243.632068] ? lock_release+0xd9/0x300
[40243.632696] ? __mutex_unlock_slowpath+0x3e/0x340
[40243.633429] ? lock_release+0xd9/0x300
[40243.634052] handle_cap_grant+0xcf6/0x1060
[40243.634745] ceph_handle_caps+0x122b/0x2110
[40243.635415] mds_dispatch+0x5bd/0x2160
[40243.636034] ? ceph_con_process_message+0x65/0x190
[40243.636828] ? lock_release+0xd9/0x300
[40243.637431] ceph_con_process_message+0x7a/0x190
[40243.638184] ? kfree+0x311/0x4f0
[40243.638749] ? kfree+0x311/0x4f0
[40243.639268] process_message+0x16/0x1a0
[40243.639915] ? sg_free_table+0x39/0x90
[40243.640572] ceph_con_v2_try_read+0xf58/0x2120
[40243.641255] ? lock_acquire+0xc8/0x300
[40243.641863] ceph_con_workfn+0x151/0x820
[40243.642493] process_one_work+0x22f/0x630
[40243.643093] ? process_one_work+0x254/0x630
[40243.643770] worker_thread+0x1e2/0x400
[40243.644332] ? __pfx_worker_thread+0x10/0x10
[40243.645020] kthread+0x109/0x140
[40243.645560] ? __pfx_kthread+0x10/0x10
[40243.646125] ret_from_fork+0x3f8/0x480
[40243.646752] ? __pfx_kthread+0x10/0x10
[40243.647316] ? __pfx_kthread+0x10/0x10
[40243.647919] ret_from_fork_asm+0x1a/0x30
[40243.648556] </TASK>
[40243.648902] Modules linked in: overlay hctr2 libpolyval chacha libchacha adiantum libnh libpoly1305 essiv intel_rapl_msr intel_rapl_common intel_uncore_frequency_common skx_edac_common nfit kvm_intel kvm irqbypass joydev ghash_clmulni_intel aesni_intel rapl input_leds mac_hid psmouse vga16fb serio_raw vgastate floppy i2c_piix4 pata_acpi bochs qemu_fw_cfg i2c_smbus sch_fq_codel rbd dm_crypt msr parport_pc ppdev lp parport efi_pstore
[40243.654766] ---[ end trace 0000000000000000 ]---
Commit d93231a6bc8a ("ceph: prevent a client from exceeding the MDS
maximum xattr size") moved the required_blob_size computation to before
the __build_xattrs() call, introducing a race.
__build_xattrs() releases and reacquires i_ceph_lock during execution.
In that window, handle_cap_grant() may update i_xattrs.blob with a
newer MDS-provided blob and bump i_xattrs.version. When
__bui
---truncated---
CVSS Score
5.5
EPSS Score
0.002
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
ceph: fix a buffer leak in __ceph_setxattr()
The old_blob in __ceph_setxattr() can store
ci->i_xattrs.prealloc_blob value during the retry.
However, it is never called the ceph_buffer_put()
for the old_blob object. This patch fixes the issue of
the buffer leak.
CVSS Score
7.8
EPSS Score
0.002
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Bound MIDI endpoint descriptor scans
snd_usbmidi_get_ms_info() validates the internal MIDIStreaming endpoint
descriptor size before using baAssocJackID[], but the descriptor walker can
still return a class-specific endpoint descriptor whose bLength exceeds the
remaining bytes in the endpoint-extra scan.
That leaves later flexible-array reads bounded by bLength, but not by the
remaining bytes in the endpoint-extra scan.
Stop walking when bLength is zero or
extends past the remaining endpoint-extra scan.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Bound MIDI 2.0 endpoint descriptor scans
The USB MIDI 2.0 endpoint parser has the same descriptor walking
pattern as the legacy MIDI parser. It validates bLength against
bNumGrpTrmBlock before reading baAssoGrpTrmBlkID[], but not against the
remaining bytes in the endpoint-extra scan.
A malformed device can therefore make later baAssoGrpTrmBlkID[] reads
consume bytes past the walked descriptor.
Reject zero-length and overlong descriptors while walking endpoint
extras.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
drm/ttm: Fix ttm_bo_swapout() infinite LRU walk on swapout failure
When ttm_tt_swapout() fails, the current code calls
ttm_resource_add_bulk_move() followed by ttm_resource_move_to_lru_tail()
to restore the resource's bulk_move membership.
However, ttm_resource_move_to_lru_tail() places the resource at the tail
of the LRU list which, relative to the walk cursor's hitch node (placed
immediately after the resource when it was yielded), puts the resource
*in front of the* the hitch. The next list_for_each_entry_continue() from
the hitch finds the same resource again, causing an infinite loop.
Fix by deferring del_bulk_move to the success path only.
On the success path, TTM_TT_FLAG_SWAPPED has just been set by
ttm_tt_swapout() but the resource is still tracked in the bulk_move range,
so ttm_resource_del_bulk_move()'s !ttm_resource_unevictable() guard would
incorrectly skip the removal. Introduce
ttm_resource_del_bulk_move_unevictable() which bypasses that guard.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
drm/ttm: Fix ttm_bo_shrink() infinite LRU walk on backup failure
Apply the same fix as b2ed01e7ad ("drm/ttm: Fix ttm_bo_swapout()
infinite LRU walk on swapout failure") to the ttm_bo_shrink() path.
Move del_bulk_move from before the backup to after success only,
using ttm_resource_del_bulk_move_unevictable() since the resource
is now unevictable once fully backed up.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
drm/xe/dma-buf: fix UAF with retry loop
Retry doesn't work here, since bo will be freed on error, leading to
UAF. However, now that we do the alloc & init before the attach, we can
now combine this as one unit and have the init do the alloc for us. This
should make the retry safe.
Reported by Sashiko.
v2: Fix up the error unwind (CI)
(cherry picked from commit 479669418253e0f27f8cf5db01a731352ea592e7)
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
drm/xe/dma-buf: handle empty bo and UAF races
There look to be some nasty races here when triggering the
invalidate_mappings hook:
1) We do xe_bo_alloc() followed by the attach, before the actual full bo
init step in xe_dma_buf_init_obj(). However the bo is visible on the
attachments list after the attach. This is bad since exporter driver,
say amdgpu, can at any time call back into our invalidate_mappings hook,
with an empty/bogus bo, leading to potential bugs/crashes.
2) Similar to 1) but here we get a UAF, when the invalidate_mappings
hook is triggered. For example, we get as far as xe_bo_init_locked()
but this fails in some way. But here the bo will be freed on error, but
we still have it attached from dma-buf pov, so if the
invalidate_mappings is now triggered then the bo we access is gone and
we trigger UAF and more bugs/crashes.
To fix this, move the attach step until after we actually have a fully
set up buffer object. Note that the bo is not published to userspace
until later, so not sure what the comment "Don't publish the bo
until we have a valid attachment", is referring to.
We have at least two different customers reporting hitting a NULL ptr
deref in evict_flags when importing something from amdgpu, followed by
triggering the evict flow. Hit rate is also pretty low, which would
hint at some kind of race, so something like 1) or 2) might explain
this.
v2:
- Shuffle the order of the ops slightly (no functional change)
- Improve the comment to better explain the ordering (Matt B)
(cherry picked from commit af1f2ad0c59fe4e2f924c526f66e968289d77971)
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24