Linux: >> Linux Kernel >> 2.6.28.2 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
i2c: core: fix adapter registration race
Adapters can be looked up based on their id using i2c_get_adapter()
which takes a reference to the embedded struct device.
Make sure that the adapter (including its struct device) has been
initialised before adding it to the IDR to avoid accessing uninitialised
data which could, for example, lead to NULL-pointer dereferences or
use-after-free.
Note that the i2c-dev chardev, which is registered from a bus notifier,
currently uses i2c_get_adapter() so the adapter needs to be added to the
IDR before registration.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
fbdev: Fix fb_new_modelist to prevent null-ptr-deref in fb_videomode_to_var
info->var, a framebuffer's current mode, is expected to have a matching
entry in info->modelist. var_to_display() relies on this and treats a
failed fb_match_mode() as "This should not happen". fb_set_var() keeps it
true by adding the mode to the list on every change, and
do_register_framebuffer() does the same at registration.
store_modes() replaces the modelist from userspace. fb_new_modelist()
validates the new modes but does not check that info->var still has a
match. It relies on fbcon_new_modelist() to re-point consoles, but that
only handles consoles mapped to the framebuffer. With fbcon unbound there
are none, so info->var is left describing a mode that is no longer in the
list.
A later console takeover runs var_to_display(), where fb_match_mode()
returns NULL and leaves fb_display[i].mode NULL. fbcon_switch() passes it
to display_to_var(), and fb_videomode_to_var() dereferences the NULL mode.
Keep the current mode in the list in fb_new_modelist(), the same way
fb_set_var() does.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
nfsd: fix posix_acl leak on SETACL decode failure
nfsaclsvc_decode_setaclargs() and nfs3svc_decode_setaclargs() each
call nfs_stream_decode_acl() twice, first for NFS_ACL and then for
NFS_DFACL. Each successful call transfers ownership of a freshly
allocated posix_acl into argp->acl_access or argp->acl_default. If
the first call succeeds but the second fails, the decoder returns
false and argp->acl_access is left dangling.
ACLPROC2_SETACL.pc_release was wired to nfssvc_release_attrstat and
ACLPROC3_SETACL.pc_release was wired to nfs3svc_release_fhandle.
Both only call fh_put() and have no knowledge of the ACL fields on
argp. The posix_acl_release() pairs sat at the out: labels inside
nfsacld_proc_setacl() and nfsd3_proc_setacl(), but svc_process()
skips pc_func when pc_decode returns false, so that cleanup is
unreachable on decode failure:
svc_process_common()
pc_decode() /* decode_setaclargs: false */
/* pc_func skipped */
pc_release() /* fh_put only -- ACLs leaked */
The orphaned posix_acl is leaked for the lifetime of the server.
Fix by adding nfsaclsvc_release_setacl() and nfs3svc_release_setacl(),
which release both argp->acl_access and argp->acl_default in addition
to fh_put(), and wiring them as pc_release for their respective SETACL
procedures. pc_release runs on every path svc_process() takes after
decode, including decode failure, so the posix_acl_release() pairs are
removed from the proc functions' out: labels to keep ownership in one
place. This matches the existing release_getacl() pattern used by
the sibling GETACL procedures.
CVSS Score
7.5
EPSS Score
0.005
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
udf: reject descriptors with oversized CRC length
udf_read_tagged() skips CRC verification when descCRCLength +
sizeof(struct tag) exceeds the block size. A crafted UDF image can
set descCRCLength to an oversized value to bypass CRC validation
entirely; the descriptor is then accepted based solely on the 8-bit
tag checksum, which is trivially recomputable.
Reject such descriptors instead of silently accepting them. A
legitimate single-block descriptor should never have a CRC length that
exceeds the block.
CVSS Score
8.4
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack: destroy stale expectfn expectations on unregister
NAT helpers such as nf_nat_h323 store a raw pointer to module text in
exp->expectfn (e.g. ip_nat_q931_expect). nf_ct_helper_expectfn_unregister()
only unlinks the callback descriptor and never walks the expectation table,
so an expectation pending at module removal survives with a dangling
exp->expectfn into freed module text.
When the expected connection arrives, init_conntrack() invokes
exp->expectfn(), now a stale pointer into the unloaded module. Reproduced
on a KASAN build by loading the H.323 helpers, creating a Q.931
expectation, unloading nf_nat_h323, then connecting to the expected port:
Oops: int3: 0000 [#1] SMP KASAN NOPTI
RIP: 0010:0xffffffffa06102d1
init_conntrack.isra.0 (net/netfilter/nf_conntrack_core.c:1862)
nf_conntrack_in (net/netfilter/nf_conntrack_core.c:2049)
ipv4_conntrack_local (net/netfilter/nf_conntrack_proto.c:223)
nf_hook_slow (net/netfilter/core.c:619)
__ip_local_out (net/ipv4/ip_output.c:120)
__tcp_transmit_skb (net/ipv4/tcp_output.c:1715)
tcp_connect (net/ipv4/tcp_output.c:4374)
tcp_v4_connect (net/ipv4/tcp_ipv4.c:345)
__sys_connect (net/socket.c:2167)
Modules linked in: nf_conntrack_h323 [last unloaded: nf_nat_h323]
Reaching the dangling state requires CAP_SYS_MODULE in the initial user
namespace to remove a NAT helper that still has live expectations, so this
is a robustness fix; leaving an expectation pointing at freed text is wrong
regardless.
Add nf_ct_helper_expectfn_destroy(), which walks the expectation table and
drops every expectation whose ->expectfn matches the descriptor being torn
down. Call it from each NAT helper's exit path after the existing RCU grace
period, so no expectation outlives the code it points at and no extra
synchronize_rcu() is introduced. With the fix, the same reproducer runs to
completion without the Oops.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-01
In the Linux kernel, the following vulnerability has been resolved:
agp/amd64: Fix broken error propagation in agp_amd64_probe()
A NULL pointer dereference was observed in the AMD64 AGP driver when
running in a virtualized environment (e.g. qemu/kvm) without a physical
AMD northbridge. The crash occurs in amd64_fetch_size() when attempting
to dereference the pointer returned by node_to_amd_nb(0).
The root cause of this crash is broken error propagation in
agp_amd64_probe(): When no AMD northbridges are found, cache_nbs()
correctly returns -ENODEV. However, the probe function erroneously
checks the return value against exactly -1, rather than < 0.
As a result, the hardware absence error is masked, allowing the driver
to improperly proceed with initialization. It eventually calls
agp_add_bridge(), which invokes amd64_fetch_size(). Since the hardware
does not exist, node_to_amd_nb(0) returns NULL, leading to a General
Protection Fault (GPF) when accessing its ->misc member.
Fix the issue by correcting the error check in agp_amd64_probe() to
abort properly when cache_nbs() returns any negative error code. This
prevents the driver from erroneously proceeding without hardware, thereby
avoiding the subsequent NULL pointer dereference at its source.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-29
In the Linux kernel, the following vulnerability has been resolved:
scsi: sg: Resolve soft lockup issue when opening /dev/sgX
The parameter def_reserved_size defines the default buffer size reserved
for each Sg_fd and should be restricted to a range between 0 and 1,048,576
(see https://tldp.org/HOWTO/SCSI-Generic-HOWTO/proc.html). Although the
function sg_proc_write_dressz enforces this limit, it is possible to bypass
it by directly modifying the module parameter as shown below, which then
causes a soft lockup:
echo -1 > /sys/module/sg/parameters/def_reserved_size
exec 4<> /dev/sg0
watchdog: BUG: soft lockup - CPU#5 stuck for 26 seconds! [bash:537]
Modules loaded:
CPU: 5 UID: 0 PID: 537 Command: bash, kernel version 6.19.0-rc3+ #134,
PREEMPT disabled
Hardware: QEMU Standard PC (i440FX + PIIX, 1996), BIOS version
1.16.1-2.fc37 dated 04/01/2014
...
Call Trace:
sg_build_reserve+0x5c/0xa0
sg_add_sfp+0x168/0x270
sg_open+0x16e/0x340
chrdev_open+0xbe/0x230
do_dentry_open+0x175/0x480
vfs_open+0x34/0xf0
do_open+0x265/0x3d0
path_openat+0x110/0x290
do_filp_open+0xc3/0x170
do_sys_openat2+0x71/0xe0
__x64_sys_openat+0x6d/0xa0
do_syscall_64+0x62/0x310
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The fix is to use module_param_cb to validate and reject invalid values
assigned to def_reserved_size.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-26
In the Linux kernel, the following vulnerability has been resolved:
net: phonet: do not BUG_ON() in pn_socket_autobind() on failed bind
syzbot reported a kernel BUG triggered from pn_socket_sendmsg() via
pn_socket_autobind():
kernel BUG at net/phonet/socket.c:213!
RIP: 0010:pn_socket_autobind net/phonet/socket.c:213 [inline]
RIP: 0010:pn_socket_sendmsg+0x240/0x250 net/phonet/socket.c:421
Call Trace:
sock_sendmsg_nosec+0x112/0x150 net/socket.c:797
__sock_sendmsg net/socket.c:812 [inline]
__sys_sendto+0x402/0x590 net/socket.c:2280
...
pn_socket_autobind() calls pn_socket_bind() with port 0 and, on
-EINVAL, assumes the socket was already bound and asserts that the
port is non-zero:
err = pn_socket_bind(sock, ..., sizeof(struct sockaddr_pn));
if (err != -EINVAL)
return err;
BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
return 0; /* socket was already bound */
However pn_socket_bind() also returns -EINVAL when sk->sk_state is not
TCP_CLOSE, even when the socket has never been bound and pn_port() is
still 0. In that case the BUG_ON() fires and panics the kernel from a
user-triggerable path.
Treat the "bind returned -EINVAL but pn_port() is still 0" case as a
regular error and propagate -EINVAL to the caller instead of crashing.
Existing callers already translate a non-zero return from
pn_socket_autobind() into -ENOBUFS/-EAGAIN, so returning -EINVAL here
only changes behaviour from panic to a normal errno.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-26
In the Linux kernel, the following vulnerability has been resolved:
ipv6: mcast: Fix use-after-free when processing MLD queries
When processing an MLD query, a pointer to the multicast group address
is retrieved when initially parsing the packet. This pointer is later
dereferenced without being reloaded despite the fact that the skb header
might have been reallocated following the pskb_may_pull() calls, leading
to a use-after-free [1].
Fix by copying the multicast group address when the packet is initially
parsed.
[1]
BUG: KASAN: slab-use-after-free in __mld_query_work (net/ipv6/mcast.c:1512)
Read of size 8 at addr ffff8881154b8e90 by task kworker/4:1/118
Workqueue: mld mld_query_work
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:94 lib/dump_stack.c:120)
print_address_description.constprop.0 (mm/kasan/report.c:378)
print_report (mm/kasan/report.c:482)
kasan_report (mm/kasan/report.c:595)
__mld_query_work (net/ipv6/mcast.c:1512)
mld_query_work (net/ipv6/mcast.c:1563)
process_one_work (kernel/workqueue.c:3314)
worker_thread (kernel/workqueue.c:3397 kernel/workqueue.c:3478)
kthread (kernel/kthread.c:436)
ret_from_fork (arch/x86/kernel/process.c:158)
ret_from_fork_asm (arch/x86/entry/entry_64.S:245)
</TASK>
[...]
Freed by task 118:
kasan_save_stack (mm/kasan/common.c:57)
kasan_save_track (mm/kasan/common.c:78)
kasan_save_free_info (mm/kasan/generic.c:584)
__kasan_slab_free (mm/kasan/common.c:253 mm/kasan/common.c:285)
kfree (./include/linux/kasan.h:235 mm/slub.c:2689 mm/slub.c:6251 mm/slub.c:6566)
pskb_expand_head (net/core/skbuff.c:2335)
__pskb_pull_tail (net/core/skbuff.c:2878 (discriminator 4))
__mld_query_work (net/ipv6/mcast.c:1495 (discriminator 1))
mld_query_work (net/ipv6/mcast.c:1563)
process_one_work (kernel/workqueue.c:3314)
worker_thread (kernel/workqueue.c:3397 kernel/workqueue.c:3478)
kthread (kernel/kthread.c:436)
ret_from_fork (arch/x86/kernel/process.c:158)
ret_from_fork_asm (arch/x86/entry/entry_64.S:245)
CVSS Score
8.8
EPSS Score
0.002
Published
2026-06-25
In the Linux kernel, the following vulnerability has been resolved:
netfilter: conntrack_irc: fix possible out-of-bounds read
When parsing fails after we've matched the command string we
should bail out instead of trying to match a different command.
This helper should be deprecated, given prevalence of TLS I doubt it has
any relevance in 2026.
CVSS Score
8.2
EPSS Score
0.003
Published
2026-06-25