Linux: >> Linux Kernel >> 4.19.75 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
nfsd: never defer requests during idmap lookup
During v4 request compound arg decoding, some ops (e.g. SETATTR)
can trigger idmap lookup upcalls. When those upcall responses get
delayed beyond the allowed time limit, cache_check() will mark the
request for deferral and cause it to be dropped.
This prevents nfs4svc_encode_compoundres from being executed, and
thus the session slot flag NFSD4_SLOT_INUSE never gets cleared.
Subsequent client requests will fail with NFSERR_JUKEBOX, given
that the slot will be marked as in-use, making the SEQUENCE op
fail.
Fix this by making sure that the RQ_USEDEFERRAL flag is always
clear during nfs4svc_decode_compoundargs(), since no v4 request
should ever be deferred.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
ext4: don't set EXT4_GET_BLOCKS_CONVERT when splitting before submitting I/O
When allocating blocks during within-EOF DIO and writeback with
dioread_nolock enabled, EXT4_GET_BLOCKS_PRE_IO was set to split an
existing large unwritten extent. However, EXT4_GET_BLOCKS_CONVERT was
set when calling ext4_split_convert_extents(), which may potentially
result in stale data issues.
Assume we have an unwritten extent, and then DIO writes the second half.
[UUUUUUUUUUUUUUUU] on-disk extent U: unwritten extent
[UUUUUUUUUUUUUUUU] extent status tree
|<- ->| ----> dio write this range
First, ext4_iomap_alloc() call ext4_map_blocks() with
EXT4_GET_BLOCKS_PRE_IO, EXT4_GET_BLOCKS_UNWRIT_EXT and
EXT4_GET_BLOCKS_CREATE flags set. ext4_map_blocks() find this extent and
call ext4_split_convert_extents() with EXT4_GET_BLOCKS_CONVERT and the
above flags set.
Then, ext4_split_convert_extents() calls ext4_split_extent() with
EXT4_EXT_MAY_ZEROOUT, EXT4_EXT_MARK_UNWRIT2 and EXT4_EXT_DATA_VALID2
flags set, and it calls ext4_split_extent_at() to split the second half
with EXT4_EXT_DATA_VALID2, EXT4_EXT_MARK_UNWRIT1, EXT4_EXT_MAY_ZEROOUT
and EXT4_EXT_MARK_UNWRIT2 flags set. However, ext4_split_extent_at()
failed to insert extent since a temporary lack -ENOSPC. It zeroes out
the first half but convert the entire on-disk extent to written since
the EXT4_EXT_DATA_VALID2 flag set, but left the second half as unwritten
in the extent status tree.
[0000000000SSSSSS] data S: stale data, 0: zeroed
[WWWWWWWWWWWWWWWW] on-disk extent W: written extent
[WWWWWWWWWWUUUUUU] extent status tree
Finally, if the DIO failed to write data to the disk, the stale data in
the second half will be exposed once the cached extent entry is gone.
Fix this issue by not passing EXT4_GET_BLOCKS_CONVERT when splitting
an unwritten extent before submitting I/O, and make
ext4_split_convert_extents() to zero out the entire extent range
to zero for this case, and also mark the extent in the extent status
tree for consistency.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
crypto: ccree - fix a memory leak in cc_mac_digest()
Add cc_unmap_result() if cc_map_hash_request_final()
fails to prevent potential memory leak.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
staging: greybus: lights: avoid NULL deref
gb_lights_light_config() stores channel_count before allocating the
channels array. If kcalloc() fails, gb_lights_release() iterates the
non-zero count and dereferences light->channels, which is NULL.
Allocate channels first and only then publish channels_count so the
cleanup path can't walk a NULL pointer.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
apparmor: fix invalid deref of rawdata when export_binary is unset
If the export_binary parameter is disabled on runtime, profiles that
were loaded before that will still have their rawdata stored in
apparmorfs, with a symbolic link to the rawdata on the policy
directory. When one of those profiles are replaced, the rawdata is set
to NULL, but when trying to resolve the symbolic links to rawdata for
that profile, it will try to dereference profile->rawdata->name when
profile->rawdata is now NULL causing an oops. Fix it by checking if
rawdata is set.
[ 168.653080] BUG: kernel NULL pointer dereference, address: 0000000000000088
[ 168.657420] #PF: supervisor read access in kernel mode
[ 168.660619] #PF: error_code(0x0000) - not-present page
[ 168.663613] PGD 0 P4D 0
[ 168.665450] Oops: Oops: 0000 [#1] SMP NOPTI
[ 168.667836] CPU: 1 UID: 0 PID: 1729 Comm: ls Not tainted 6.19.0-rc7+ #3 PREEMPT(voluntary)
[ 168.672308] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 168.679327] RIP: 0010:rawdata_get_link_base.isra.0+0x23/0x330
[ 168.682768] Code: 90 90 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 18 48 89 55 d0 48 85 ff 0f 84 e3 01 00 00 <48> 83 3c 25 88 00 00 00 00 0f 84 d4 01 00 00 49 89 f6 49 89 cc e8
[ 168.689818] RSP: 0018:ffffcdcb8200fb80 EFLAGS: 00010282
[ 168.690871] RAX: ffffffffaee74ec0 RBX: 0000000000000000 RCX: ffffffffb0120158
[ 168.692251] RDX: ffffcdcb8200fbe0 RSI: ffff88c187c9fa80 RDI: ffff88c186c98a80
[ 168.693593] RBP: ffffcdcb8200fbc0 R08: 0000000000000000 R09: 0000000000000000
[ 168.694941] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88c186c98a80
[ 168.696289] R13: 00007fff005aaa20 R14: 0000000000000080 R15: ffff88c188f4fce0
[ 168.697637] FS: 0000790e81c58280(0000) GS:ffff88c20a957000(0000) knlGS:0000000000000000
[ 168.699227] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 168.700349] CR2: 0000000000000088 CR3: 000000012fd3e000 CR4: 0000000000350ef0
[ 168.701696] Call Trace:
[ 168.702325] <TASK>
[ 168.702995] rawdata_get_link_data+0x1c/0x30
[ 168.704145] vfs_readlink+0xd4/0x160
[ 168.705152] do_readlinkat+0x114/0x180
[ 168.706214] __x64_sys_readlink+0x1e/0x30
[ 168.708653] x64_sys_call+0x1d77/0x26b0
[ 168.709525] do_syscall_64+0x81/0x500
[ 168.710348] ? do_statx+0x72/0xb0
[ 168.711109] ? putname+0x3e/0x80
[ 168.711845] ? __x64_sys_statx+0xb7/0x100
[ 168.712711] ? x64_sys_call+0x10fc/0x26b0
[ 168.713577] ? do_syscall_64+0xbf/0x500
[ 168.714412] ? do_user_addr_fault+0x1d2/0x8d0
[ 168.715404] ? irqentry_exit+0xb2/0x740
[ 168.716359] ? exc_page_fault+0x90/0x1b0
[ 168.717307] entry_SYSCALL_64_after_hwframe+0x76/0x7e
CVSS Score
5.5
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
cpuidle: Skip governor when only one idle state is available
On certain platforms (PowerNV systems without a power-mgt DT node),
cpuidle may register only a single idle state. In cases where that
single state is a polling state (state 0), the ladder governor may
incorrectly treat state 1 as the first usable state and pass an
out-of-bounds index. This can lead to a NULL enter callback being
invoked, ultimately resulting in a system crash.
[ 13.342636] cpuidle-powernv : Only Snooze is available
[ 13.351854] Faulting instruction address: 0x00000000
[ 13.376489] NIP [0000000000000000] 0x0
[ 13.378351] LR [c000000001e01974] cpuidle_enter_state+0x2c4/0x668
Fix this by adding a bail-out in cpuidle_select() that returns state 0
directly when state_count <= 1, bypassing the governor and keeping the
tick running.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
bonding: alb: fix UAF in rlb_arp_recv during bond up/down
The ALB RX path may access rx_hashtbl concurrently with bond
teardown. During rapid bond up/down cycles, rlb_deinitialize()
frees rx_hashtbl while RX handlers are still running, leading
to a null pointer dereference detected by KASAN.
However, the root cause is that rlb_arp_recv() can still be accessed
after setting recv_probe to NULL, which is actually a use-after-free
(UAF) issue. That is the reason for using the referenced commit in the
Fixes tag.
[ 214.174138] Oops: general protection fault, probably for non-canonical address 0xdffffc000000001d: 0000 [#1] SMP KASAN PTI
[ 214.186478] KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef]
[ 214.194933] CPU: 30 UID: 0 PID: 2375 Comm: ping Kdump: loaded Not tainted 6.19.0-rc8+ #2 PREEMPT(voluntary)
[ 214.205907] Hardware name: Dell Inc. PowerEdge R730/0WCJNT, BIOS 2.14.0 01/14/2022
[ 214.214357] RIP: 0010:rlb_arp_recv+0x505/0xab0 [bonding]
[ 214.220320] Code: 0f 85 2b 05 00 00 48 b8 00 00 00 00 00 fc ff df 40 0f b6 ed 48 c1 e5 06 49 03 ad 78 01 00 00 48 8d 7d 28 48 89 fa 48 c1 ea 03 <0f> b6
04 02 84 c0 74 06 0f 8e 12 05 00 00 80 7d 28 00 0f 84 8c 00
[ 214.241280] RSP: 0018:ffffc900073d8870 EFLAGS: 00010206
[ 214.247116] RAX: dffffc0000000000 RBX: ffff888168556822 RCX: ffff88816855681e
[ 214.255082] RDX: 000000000000001d RSI: dffffc0000000000 RDI: 00000000000000e8
[ 214.263048] RBP: 00000000000000c0 R08: 0000000000000002 R09: ffffed11192021c8
[ 214.271013] R10: ffff8888c9010e43 R11: 0000000000000001 R12: 1ffff92000e7b119
[ 214.278978] R13: ffff8888c9010e00 R14: ffff888168556822 R15: ffff888168556810
[ 214.286943] FS: 00007f85d2d9cb80(0000) GS:ffff88886ccb3000(0000) knlGS:0000000000000000
[ 214.295966] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 214.302380] CR2: 00007f0d047b5e34 CR3: 00000008a1c2e002 CR4: 00000000001726f0
[ 214.310347] Call Trace:
[ 214.313070] <IRQ>
[ 214.315318] ? __pfx_rlb_arp_recv+0x10/0x10 [bonding]
[ 214.320975] bond_handle_frame+0x166/0xb60 [bonding]
[ 214.326537] ? __pfx_bond_handle_frame+0x10/0x10 [bonding]
[ 214.332680] __netif_receive_skb_core.constprop.0+0x576/0x2710
[ 214.339199] ? __pfx_arp_process+0x10/0x10
[ 214.343775] ? sched_balance_find_src_group+0x98/0x630
[ 214.349513] ? __pfx___netif_receive_skb_core.constprop.0+0x10/0x10
[ 214.356513] ? arp_rcv+0x307/0x690
[ 214.360311] ? __pfx_arp_rcv+0x10/0x10
[ 214.364499] ? __lock_acquire+0x58c/0xbd0
[ 214.368975] __netif_receive_skb_one_core+0xae/0x1b0
[ 214.374518] ? __pfx___netif_receive_skb_one_core+0x10/0x10
[ 214.380743] ? lock_acquire+0x10b/0x140
[ 214.385026] process_backlog+0x3f1/0x13a0
[ 214.389502] ? process_backlog+0x3aa/0x13a0
[ 214.394174] __napi_poll.constprop.0+0x9f/0x370
[ 214.399233] net_rx_action+0x8c1/0xe60
[ 214.403423] ? __pfx_net_rx_action+0x10/0x10
[ 214.408193] ? lock_acquire.part.0+0xbd/0x260
[ 214.413058] ? sched_clock_cpu+0x6c/0x540
[ 214.417540] ? mark_held_locks+0x40/0x70
[ 214.421920] handle_softirqs+0x1fd/0x860
[ 214.426302] ? __pfx_handle_softirqs+0x10/0x10
[ 214.431264] ? __neigh_event_send+0x2d6/0xf50
[ 214.436131] do_softirq+0xb1/0xf0
[ 214.439830] </IRQ>
The issue is reproducible by repeatedly running
ip link set bond0 up/down while receiving ARP messages, where
rlb_arp_recv() can race with rlb_deinitialize() and dereference
a freed rx_hashtbl entry.
Fix this by setting recv_probe to NULL and then calling
synchronize_net() to wait for any concurrent RX processing to finish.
This ensures that no RX handler can access rx_hashtbl after it is freed
in bond_alb_deinitialize().
CVSS Score
7.8
EPSS Score
0.001
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
drm/exynos: vidi: use priv->vidi_dev for ctx lookup in vidi_connection_ioctl()
vidi_connection_ioctl() retrieves the driver_data from drm_dev->dev to
obtain a struct vidi_context pointer. However, drm_dev->dev is the
exynos-drm master device, and the driver_data contained therein is not
the vidi component device, but a completely different device.
This can lead to various bugs, ranging from null pointer dereferences and
garbage value accesses to, in unlucky cases, out-of-bounds errors,
use-after-free errors, and more.
To resolve this issue, we need to store/delete the vidi device pointer in
exynos_drm_private->vidi_dev during bind/unbind, and then read this
exynos_drm_private->vidi_dev within ioctl() to obtain the correct
struct vidi_context pointer.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
drm/exynos: vidi: fix to avoid directly dereferencing user pointer
In vidi_connection_ioctl(), vidi->edid(user pointer) is directly
dereferenced in the kernel.
This allows arbitrary kernel memory access from the user space, so instead
of directly accessing the user pointer in the kernel, we should modify it
to copy edid to kernel memory using copy_from_user() and use it.
CVSS Score
7.1
EPSS Score
0.001
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
hfsplus: return error when node already exists in hfs_bnode_create
When hfs_bnode_create() finds that a node is already hashed (which should
not happen in normal operation), it currently returns the existing node
without incrementing its reference count. This causes a reference count
inconsistency that leads to a kernel panic when the node is later freed
in hfs_bnode_put():
kernel BUG at fs/hfsplus/bnode.c:676!
BUG_ON(!atomic_read(&node->refcnt))
This scenario can occur when hfs_bmap_alloc() attempts to allocate a node
that is already in use (e.g., when node 0's bitmap bit is incorrectly
unset), or due to filesystem corruption.
Returning an existing node from a create path is not normal operation.
Fix this by returning ERR_PTR(-EEXIST) instead of the node when it's
already hashed. This properly signals the error condition to callers,
which already check for IS_ERR() return values.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-27