Linux: >> Linux Kernel >> 7.0.3 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
ipv6: ioam: refresh hdr pointer before ioam6_event()
Reported by Sashiko:
In ipv6_hop_ioam(), the hdr pointer is initialized to point into the
skb's linear data buffer. Later, the code calls skb_ensure_writable(),
which might reallocate the buffer:
if (skb_ensure_writable(skb, optoff + 2 + hdr->opt_len))
goto drop;
/* Trace pointer may have changed */
trace = (struct ioam6_trace_hdr *)(skb_network_header(skb)
+ optoff + sizeof(*hdr));
ioam6_fill_trace_data(skb, ns, trace, true);
ioam6_event(IOAM6_EVENT_TRACE, dev_net(skb->dev),
GFP_ATOMIC, (void *)trace, hdr->opt_len - 2);
If the skb is cloned or lacks sufficient linear headroom,
skb_ensure_writable() will invoke pskb_expand_head(), which reallocates
the skb's data buffer and frees the old one, invalidating pointers to
it. While the code recalculates the trace pointer immediately after the
call to skb_ensure_writable(), it fails to recalculate the hdr pointer.
This patch fixes the above by recalculating the hdr pointer before
passing hdr->opt_len to ioam6_event(), so that we avoid any UaF.
CVSS Score
9.8
EPSS Score
0.005
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
ALSA: asihpi: Fix potential OOB array access at reading cache
find_control() to retrieve a cached info accesses the array with the
given index blindly, which may lead to an OOB array access.
Add a sanity check for avoiding it.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
ALSA: pcm: Don't setup bogus iov_iter for silencing
At transition to the iov_iter for PCM data transfer, we blindly
applied the iov_iter setup also for silencing (i.e. data = NULL), and
it leads to a calculation of bogus iov_iter. Fortunately this didn't
cause troubles on most of architectures but it goes wrong on RISC-V
now, causing a NULL dereference.
Handle the NULL data case to treat the silencing in interleaved_copy()
for addressing the bug above. noninterleaved_copy() has already the
NULL data handling, so it doesn't need changes.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (pmbus/adm1266) widen blackbox-info buffer to I2C_SMBUS_BLOCK_MAX
adm1266_nvmem_read_blackbox() declares a 5-byte stack buffer and
passes it to i2c_smbus_read_block_data() to retrieve the 4-byte
BLACKBOX_INFO response. i2c_smbus_read_block_data() does not honour
caller buffer sizes -- it memcpy()s data.block[0] bytes from the
SMBus transaction (where data.block[0] is the length byte returned by
the slave device, up to I2C_SMBUS_BLOCK_MAX = 32):
memcpy(values, &data.block[1], data.block[0]);
If the device returns any block length above 5, the call overflows
the caller's 5-byte stack buffer before the post-call
if (ret != 4)
return -EIO;
check has a chance to reject the response.
Widen the local buffer to I2C_SMBUS_BLOCK_MAX so the helper has room
for any well-formed SMBus block response, matching the convention used
by the other i2c_smbus_read_block_data() callers in this driver.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked()
Commit 96c4af418586 ("cifs: Fix locking usage for tcon fields")
refactored cifs code to change cifs_tcp_ses_lock for tc_lock around
tc_count changes.
There was missing lock around tc_count increment inside
smb2_find_smb_sess_tcon_unlocked().
CVSS Score
9.8
EPSS Score
0.005
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
smb: client: require net admin for CIFS SWN netlink
CIFS_GENL_CMD_SWN_NOTIFY is the userspace witness-notify command. The
intended sender is the cifs.witness helper, but the generic-netlink
operation currently has no capability flag, so any local process can send
RESOURCE_CHANGE or CLIENT_MOVE notifications to the in-kernel witness
handler.
The same family exposes CIFS_GENL_MCGRP_SWN without multicast-group
capability flags. Register messages sent to that group include the witness
registration id and, for NTLM-authenticated mounts, the username, domain,
and password attributes copied from the CIFS session. An unprivileged
local process should not be able to join that group and receive those
messages.
Require CAP_NET_ADMIN for incoming SWN_NOTIFY commands with
GENL_ADMIN_PERM, and require CAP_NET_ADMIN over the network namespace for
joining the SWN multicast group with GENL_MCAST_CAP_NET_ADMIN. The
cifs.witness service runs with the privileges needed for both operations.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: validate SID in parent security descriptor during ACL inheritance
Introduce smb_validate_ntsd_sid() helper to safely validate Owner SID
and Group SID inside the NT Security Descriptor (smb_ntsd) retrieved
from the parent directory.
CVSS Score
8.8
EPSS Score
0.004
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix null pointer dereference in proc_show_files()
When a SMB2 client opens a file with a durable v2 handle and then issues
SMB2 SESSION_LOGOFF, session_fd_check() clears fp->tcon = NULL on the
reconnectable file pointer but leaves the fp registered in global_ft.idr
until the durable scavenger fires (up to fp->durable_timeout seconds
later).
During that window any read of /proc/fs/ksmbd/files (mode 0400) panics
the kernel because proc_show_files() walks global_ft.idr and
unconditionally dereferences fp->tcon->id with no NULL guard.
Reproducer requires only a successful SMB2 SESSION_SETUP and a share
configured with 'durable handles = yes'. KASAN report on mainline
70390501d194:
general protection fault, probably for non-canonical address
0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
RIP: 0010:proc_show_files+0x118/0x740
Call Trace:
proc_show_files+0x118/0x740
seq_read_iter+0x4ef/0xe10
proc_reg_read_iter+0x1b7/0x280
...
Guard the dereference. A durable-disconnected fp legitimately has no
tcon; report its tree id as 0 rather than oopsing.
CVSS Score
7.5
EPSS Score
0.004
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix null pointer dereference in compare_guid_key()
session_fd_check() walks the per-inode m_op_list during durable-handle
session teardown and sets op->conn = NULL for every opinfo whose conn
matched the closing session's connection. The matching opinfo, however,
stays linked in its per-ClientGuid lease_table_list entry's lb->lease_list
because destroy_lease_table() only runs on full TCP-connection teardown,
not on SESSION_LOGOFF.
If the same TCP connection then negotiates a fresh session with the
same ClientGuid (ClientGuid is bound to NEGOTIATE, not the session, and
is unchanged across LOGOFF + SETUP) and issues a SMB2 CREATE with a
lease context on a different inode, find_same_lease_key() walks
lb->lease_list, reaches the stale opinfo, and calls compare_guid_key(),
which unconditionally dereferences opinfo->conn->ClientGUID. The conn
pointer is NULL and the kernel panics.
Reproducer requires only a successful SMB2 SESSION_SETUP and a share
configured with 'durable handles = yes'. KASAN report on mainline
70390501d194:
general protection fault, probably for non-canonical address
0xdffffc0000000069: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000348-0x000000000000034f]
Workqueue: ksmbd-io handle_ksmbd_work
RIP: 0010:bcmp+0x5b/0x230
Call Trace:
compare_guid_key+0x4b/0xd0
find_same_lease_key+0x324/0x690
smb2_open+0x6aea/0x8e60
handle_ksmbd_work+0x796/0xee0
...
Faulting address 0x348 is the offset of ClientGUID within struct
ksmbd_conn, confirming opinfo->conn was NULL.
Read opinfo->conn once and bail out if it has been cleared by a
concurrent session_fd_check(). A half-detached opinfo cannot be the
owner of an active lease, so returning 0 is the correct match result.
CVSS Score
7.5
EPSS Score
0.004
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix SID memory leak in set_posix_acl_entries_dacl() on overflow
Commit 299f962c0b02 ("ksmbd: use check_add_overflow() to prevent u16
DACL size overflow") added check_add_overflow() guards that break out
of the ACE-building loops in set_posix_acl_entries_dacl() when the
accumulated DACL size would wrap past 65535.
However, each iteration allocates a struct smb_sid via kmalloc_obj()
at the top of the loop and relies on the kfree(sid) call at the end
of the loop body (the 'pass_same_sid' label in the first loop, and
the explicit kfree at the tail of the second loop) to release it.
The newly introduced 'break' statements bypass those kfree() calls,
leaking the sid buffer every time an overflow is detected.
A malicious or malformed file with enough POSIX ACL entries to trip
the overflow check will leak one or more struct smb_sid allocations
on every request that touches the file's DACL, providing a trivial
kernel memory exhaustion vector.
Free sid before breaking out of the loops to plug the leak.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-19