Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: require 3 sub-authorities before reading sub_auth[2]
parse_dacl() compares each ACE SID against sid_unix_NFS_mode and on
match reads sid.sub_auth[2] as the file mode. If sid_unix_NFS_mode is
the prefix S-1-5-88-3 with num_subauth = 2 then compare_sids() compares
only min(num_subauth, 2) sub-authorities so a client SID with
num_subauth = 2 and sub_auth = {88, 3} will match.
If num_subauth = 2 and the ACE is placed at the very end of the security
descriptor, sub_auth[2] will be 4 bytes past end_of_acl. The
out-of-band bytes will then be masked to the low 9 bits and applied as
the file's POSIX mode, probably not something that is good to have
happen.
Fix this up by forcing the SID to actually carry a third sub-authority
before reading it at all.
CVSS Score
8.6
EPSS Score
0.001
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: validate EaNameLength in smb2_get_ea()
smb2_get_ea() reads ea_req->EaNameLength from the client request and
passes it directly to strncmp() as the comparison length without
verifying that the length of the name really is the size of the input
buffer received.
Fix this up by properly checking the size of the name based on the value
received and the overall size of the request, to prevent a later
strncmp() call to use the length as a "trusted" size of the buffer.
Without this check, uninitialized heap values might be slowly leaked to
the client.
CVSS Score
7.5
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix OOB reads parsing symlink error response
When a CREATE returns STATUS_STOPPED_ON_SYMLINK, smb2_check_message()
returns success without any length validation, leaving the symlink
parsers as the only defense against an untrusted server.
symlink_data() walks SMB 3.1.1 error contexts with the loop test "p <
end", but reads p->ErrorId at offset 4 and p->ErrorDataLength at offset
0. When the server-controlled ErrorDataLength advances p to within 1-7
bytes of end, the next iteration will read past it. When the matching
context is found, sym->SymLinkErrorTag is read at offset 4 from
p->ErrorContextData with no check that the symlink header itself fits.
smb2_parse_symlink_response() then bounds-checks the substitute name
using SMB2_SYMLINK_STRUCT_SIZE as the offset of PathBuffer from
iov_base. That value is computed as sizeof(smb2_err_rsp) +
sizeof(smb2_symlink_err_rsp), which is correct only when
ErrorContextCount == 0.
With at least one error context the symlink data sits 8 bytes deeper,
and each skipped non-matching context shifts it further by 8 +
ALIGN(ErrorDataLength, 8). The check is too short, allowing the
substitute name read to run past iov_len. The out-of-bound heap bytes
are UTF-16-decoded into the symlink target and returned to userspace via
readlink(2).
Fix this all up by making the loops test require the full context header
to fit, rejecting sym if its header runs past end, and bound the
substitute name against the actual position of sym->PathBuffer rather
than a fixed offset.
Because sub_offs and sub_len are 16bits, the pointer math will not
overflow here with the new greater-than.
CVSS Score
8.1
EPSS Score
0.001
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix off-by-8 bounds check in check_wsl_eas()
The bounds check uses (u8 *)ea + nlen + 1 + vlen as the end of the EA
name and value, but ea_data sits at offset sizeof(struct
smb2_file_full_ea_info) = 8 from ea, not at offset 0. The strncmp()
later reads ea->ea_data[0..nlen-1] and the value bytes follow at
ea_data[nlen+1..nlen+vlen], so the actual end is ea->ea_data + nlen + 1
+ vlen. Isn't pointer math fun?
The earlier check (u8 *)ea > end - sizeof(*ea) only guarantees the
8-byte header is in bounds, but since the last EA is placed within 8
bytes of the end of the response, the name and value bytes are read past
the end of iov.
Fix this mess all up by using ea->ea_data as the base for the bounds
check.
An "untrusted" server can use this to leak up to 8 bytes of kernel heap
into the EA name comparison and influence which WSL xattr the data is
interpreted as.
CVSS Score
7.1
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: renesas_usb3: validate endpoint index in standard request handlers
The GET_STATUS and SET/CLEAR_FEATURE handlers extract the endpoint
number from the host-supplied wIndex without any sort of validation.
Fix this up by validating the number of endpoints actually match up with
the number the device has before attempting to dereference a pointer
based on this math.
This is just like what was done in commit ee0d382feb44 ("usb: gadget:
aspeed_udc: validate endpoint index for ast udc") for the aspeed driver.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_phonet: fix skb frags[] overflow in pn_rx_complete()
A broken/bored/mean USB host can overflow the skb_shared_info->frags[]
array on a Linux gadget exposing a Phonet function by sending an
unbounded sequence of full-page OUT transfers.
pn_rx_complete() finalizes the skb only when req->actual < req->length,
where req->length is set to PAGE_SIZE by the gadget. If the host always
sends exactly PAGE_SIZE bytes per transfer, fp->rx.skb will never be
reset and each completion will add another fragment via
skb_add_rx_frag(). Once nr_frags exceeds MAX_SKB_FRAGS (default 17),
subsequent frag stores overwrite memory adjacent to the shinfo on the
heap.
Drop the skb and account a length error when the frag limit is reached,
matching the fix applied in t7xx by commit f0813bcd2d9d ("net: wwan:
t7xx: fix potential skb->frags overflow in RX path").
CVSS Score
5.5
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_ncm: validate minimum block_len in ncm_unwrap_ntb()
The block_len read from the host-supplied NTB header is checked against
ntb_max but has no lower bound. When block_len is smaller than
opts->ndp_size, the bounds check of:
ndp_index > (block_len - opts->ndp_size)
will underflow producing a huge unsigned value that ndp_index can never
exceed, defeating the check entirely.
The same underflow occurs in the datagram index checks against block_len
- opts->dpe_size. With those checks neutered, a malicious USB host can
choose ndp_index and datagram offsets that point past the actual
transfer, and the skb_put_data() copies adjacent kernel memory into the
network skb.
Fix this by rejecting block lengths that cannot hold at least the NTB
header plus one NDP. This will make block_len - opts->ndp_size and
block_len - opts->dpe_size both well-defined.
Commit 8d2b1a1ec9f5 ("CDC-NCM: avoid overflow in sanity checking") fixed
a related class of issues on the host side of NCM.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
vfio/xe: Reorganize the init to decouple migration from reset
Attempting to issue reset on VF devices that don't support migration
leads to the following:
BUG: unable to handle page fault for address: 00000000000011f8
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 2 UID: 0 PID: 7443 Comm: xe_sriov_flr Tainted: G S U 7.0.0-rc1-lgci-xe-xe-4588-cec43d5c2696af219-nodebug+ #1 PREEMPT(lazy)
Tainted: [S]=CPU_OUT_OF_SPEC, [U]=USER
Hardware name: Intel Corporation Alder Lake Client Platform/AlderLake-P DDR4 RVP, BIOS RPLPFWI1.R00.4035.A00.2301200723 01/20/2023
RIP: 0010:xe_sriov_vfio_wait_flr_done+0xc/0x80 [xe]
Code: ff c3 cc cc cc cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 41 54 53 <83> bf f8 11 00 00 02 75 61 41 89 f4 85 f6 74 52 48 8b 47 08 48 89
RSP: 0018:ffffc9000f7c39b8 EFLAGS: 00010202
RAX: ffffffffa04d8660 RBX: ffff88813e3e4000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000f7c39c8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888101a48800
R13: ffff88813e3e4150 R14: ffff888130d0d008 R15: ffff88813e3e40d0
FS: 00007877d3d0d940(0000) GS:ffff88890b6d3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000011f8 CR3: 000000015a762000 CR4: 0000000000f52ef0
PKRU: 55555554
Call Trace:
<TASK>
xe_vfio_pci_reset_done+0x49/0x120 [xe_vfio_pci]
pci_dev_restore+0x3b/0x80
pci_reset_function+0x109/0x140
reset_store+0x5c/0xb0
dev_attr_store+0x17/0x40
sysfs_kf_write+0x72/0x90
kernfs_fop_write_iter+0x161/0x1f0
vfs_write+0x261/0x440
ksys_write+0x69/0xf0
__x64_sys_write+0x19/0x30
x64_sys_call+0x259/0x26e0
do_syscall_64+0xcb/0x1500
? __fput+0x1a2/0x2d0
? fput_close_sync+0x3d/0xa0
? __x64_sys_close+0x3e/0x90
? x64_sys_call+0x1b7c/0x26e0
? do_syscall_64+0x109/0x1500
? __task_pid_nr_ns+0x68/0x100
? __do_sys_getpid+0x1d/0x30
? x64_sys_call+0x10b5/0x26e0
? do_syscall_64+0x109/0x1500
? putname+0x41/0x90
? do_faccessat+0x1e8/0x300
? __x64_sys_access+0x1c/0x30
? x64_sys_call+0x1822/0x26e0
? do_syscall_64+0x109/0x1500
? tick_program_event+0x43/0xa0
? hrtimer_interrupt+0x126/0x260
? irqentry_exit+0xb2/0x710
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7877d5f1c5a4
Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d a5 ea 0e 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89
RSP: 002b:00007fff48e5f908 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007877d5f1c5a4
RDX: 0000000000000001 RSI: 00007877d621b0c9 RDI: 0000000000000009
RBP: 0000000000000001 R08: 00005fb49113b010 R09: 0000000000000007
R10: 0000000000000000 R11: 0000000000000202 R12: 00007877d621b0c9
R13: 0000000000000009 R14: 00007fff48e5fac0 R15: 00007fff48e5fac0
</TASK>
This is caused by the fact that some of the xe_vfio_pci_core_device
members needed for handling reset are only initialized as part of
migration init.
Fix the problem by reorganizing the code to decouple VF init from
migration init.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
ALSA: ctxfi: Limit PTP to a single page
Commit 391e69143d0a increased CT_PTP_NUM from 1 to 4 to support 256
playback streams, but the additional pages are not used by the card
correctly. The CT20K2 hardware already has multiple VMEM_PTPAL
registers, but using them separately would require refactoring the
entire virtual memory allocation logic.
ct_vm_map() always uses PTEs in vm->ptp[0].area regardless of
CT_PTP_NUM. On AMD64 systems, a single PTP covers 512 PTEs (2M). When
aggregate memory allocations exceed this limit, ct_vm_map() tries to
access beyond the allocated space and causes a page fault:
BUG: unable to handle page fault for address: ffffd4ae8a10a000
Oops: Oops: 0002 [#1] SMP PTI
RIP: 0010:ct_vm_map+0x17c/0x280 [snd_ctxfi]
Call Trace:
atc_pcm_playback_prepare+0x225/0x3b0
ct_pcm_playback_prepare+0x38/0x60
snd_pcm_do_prepare+0x2f/0x50
snd_pcm_action_single+0x36/0x90
snd_pcm_action_nonatomic+0xbf/0xd0
snd_pcm_ioctl+0x28/0x40
__x64_sys_ioctl+0x97/0xe0
do_syscall_64+0x81/0x610
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Revert CT_PTP_NUM to 1. The 256 SRC_RESOURCE_NUM and playback_count
remain unchanged.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
staging: sm750fb: fix division by zero in ps_to_hz()
ps_to_hz() is called from hw_sm750_crtc_set_mode() without validating
that pixclock is non-zero. A zero pixclock passed via FBIOPUT_VSCREENINFO
causes a division by zero.
Fix by rejecting zero pixclock in lynxfb_ops_check_var(), consistent
with other framebuffer drivers.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-04-24