Linux: >> Linux Kernel >> 5.15.218 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
dm cache: fix write hang in passthrough mode
The invalidate_remove() function has incomplete logic for handling write
hit bios after cache invalidation. It sets up the remapping for the
overwrite_bio but then drops it immediately without submission, causing
write operations to hang.
Fix by adding a new invalidate_committed() continuation that submits
the remapped writes to the cache origin after metadata commit completes,
while using the overwrite_endio hook to ensure proper completion
sequencing. This maintains existing coherency. Also improve error
handling in invalidate_complete() to preserve the original error status
instead of using bio_io_error() unconditionally.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
drm/sun4i: backend: fix error pointer dereference
The function drm_atomic_get_plane_state() can return an error pointer
and is not checked for it. Add error pointer check.
Detected by Smatch:
drivers/gpu/drm/sun4i/sun4i_backend.c:496 sun4i_backend_atomic_check() error:
'plane_state' dereferencing possible ERR_PTR()
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
iommu/amd: Fix clone_alias() to use the original device's devid
Currently clone_alias() assumes first argument (pdev) is always the
original device pointer. This function is called by
pci_for_each_dma_alias() which based on topology decides to send
original or alias device details in first argument.
This meant that the source devid used to look up and copy the DTE
may be incorrect, leading to wrong or stale DTE entries being
propagated to alias device.
Fix this by passing the original pdev as the opaque data argument to
both the direct clone_alias() call and pci_for_each_dma_alias(). Inside
clone_alias(), retrieve the original device from data and compute devid
from it.
CVSS Score
8.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
drm/msm/dpu: fix mismatch between power and frequency
During DPU runtime suspend, calling dev_pm_opp_set_rate(dev, 0) drops
the MMCX rail to MIN_SVS while the core clock frequency remains at its
original (highest) rate. When runtime resume re-enables the clock, this
may result in a mismatch between the rail voltage and the clock rate.
For example, in the DPU bind path, the sequence could be:
cpu0: dev_sync_state -> rpmhpd_sync_state
cpu1: dpu_kms_hw_init
timeline 0 ------------------------------------------------> t
After rpmhpd_sync_state, the voltage performance is no longer guaranteed
to stay at the highest level. During dpu_kms_hw_init, calling
dev_pm_opp_set_rate(dev, 0) drops the voltage, causing the MMCX rail to
fall to MIN_SVS while the core clock is still at its maximum frequency.
When the power is re-enabled, only the clock is enabled, leading to a
situation where the MMCX rail is at MIN_SVS but the core clock is at its
highest rate. In this state, the rail cannot sustain the clock rate,
which may cause instability or system crash.
Remove the call to dev_pm_opp_set_rate(dev, 0) from dpu_runtime_suspend
to ensure the correct vote is restored when DPU resumes.
Patchwork: https://patchwork.freedesktop.org/patch/710077/
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
bpf, arm64: Fix off-by-one in check_imm signed range check
check_imm(bits, imm) is used in the arm64 BPF JIT to verify that
a branch displacement (in arm64 instruction units) fits into the
signed N-bit immediate field of a B, B.cond or CBZ/CBNZ encoding
before it is handed to the encoder. The macro currently tests for
(imm > 0 && imm >> bits) || (imm < 0 && ~imm >> bits) which admits
values in [-2^N, 2^N) — effectively a signed (N+1)-bit range. A
signed N-bit field only holds [-2^(N-1), 2^(N-1)), so the check
admits one extra bit of range on each side.
In particular, for check_imm19(), values in [2^18, 2^19) slip past
the check but do not fit into the 19-bit signed imm19 field of
B.cond. aarch64_insn_encode_immediate() then masks the raw value
into the 19-bit field, setting bit 18 (the sign bit) and flipping
a forward branch into a backward one. Same class of issue exists
for check_imm26() and the B/BL encoding. Shift by (bits - 1)
instead of bits so the actual signed N-bit range is enforced.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Take state lock for af_unix iter
When a BPF iterator program updates a sockmap, there is a race condition in
unix_stream_bpf_update_proto() where the `peer` pointer can become stale[1]
during a state transition TCP_ESTABLISHED -> TCP_CLOSE.
CPU0 bpf CPU1 close
-------- ----------
// unix_stream_bpf_update_proto()
sk_pair = unix_peer(sk)
if (unlikely(!sk_pair))
return -EINVAL;
// unix_release_sock()
skpair = unix_peer(sk);
unix_peer(sk) = NULL;
sock_put(skpair)
sock_hold(sk_pair) // UaF
More practically, this fix guarantees that the iterator program is
consistently provided with a unix socket that remains stable during
iterator execution.
[1]:
BUG: KASAN: slab-use-after-free in unix_stream_bpf_update_proto+0x155/0x490
Write of size 4 at addr ffff8881178c9a00 by task test_progs/2231
Call Trace:
dump_stack_lvl+0x5d/0x80
print_report+0x170/0x4f3
kasan_report+0xe4/0x1c0
kasan_check_range+0x125/0x200
unix_stream_bpf_update_proto+0x155/0x490
sock_map_link+0x71c/0xec0
sock_map_update_common+0xbc/0x600
sock_map_update_elem+0x19a/0x1f0
bpf_prog_bbbf56096cdd4f01_selective_dump_unix+0x20c/0x217
bpf_iter_run_prog+0x21e/0xae0
bpf_iter_unix_seq_show+0x1e0/0x2a0
bpf_seq_read+0x42c/0x10d0
vfs_read+0x171/0xb20
ksys_read+0xff/0x200
do_syscall_64+0xf7/0x5e0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Allocated by task 2236:
kasan_save_stack+0x30/0x50
kasan_save_track+0x14/0x30
__kasan_slab_alloc+0x63/0x80
kmem_cache_alloc_noprof+0x1d5/0x680
sk_prot_alloc+0x59/0x210
sk_alloc+0x34/0x470
unix_create1+0x86/0x8a0
unix_stream_connect+0x318/0x15b0
__sys_connect+0xfd/0x130
__x64_sys_connect+0x72/0xd0
do_syscall_64+0xf7/0x5e0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Freed by task 2236:
kasan_save_stack+0x30/0x50
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x70
__kasan_slab_free+0x47/0x70
kmem_cache_free+0x11c/0x590
__sk_destruct+0x432/0x6e0
unix_release_sock+0x9b3/0xf60
unix_release+0x8a/0xf0
__sock_release+0xb0/0x270
sock_close+0x18/0x20
__fput+0x36e/0xac0
fput_close_sync+0xe5/0x1a0
__x64_sys_close+0x7d/0xd0
do_syscall_64+0xf7/0x5e0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
CVSS Score
7.8
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Fix af_unix null-ptr-deref in proto update
unix_stream_connect() sets sk_state (`WRITE_ONCE(sk->sk_state,
TCP_ESTABLISHED)`) _before_ it assigns a peer (`unix_peer(sk) = newsk`).
sk_state == TCP_ESTABLISHED makes sock_map_sk_state_allowed() believe that
socket is properly set up, which would include having a defined peer. IOW,
there's a window when unix_stream_bpf_update_proto() can be called on
socket which still has unix_peer(sk) == NULL.
CPU0 bpf CPU1 connect
-------- ------------
WRITE_ONCE(sk->sk_state, TCP_ESTABLISHED)
sock_map_sk_state_allowed(sk)
...
sk_pair = unix_peer(sk)
sock_hold(sk_pair)
sock_hold(newsk)
smp_mb__after_atomic()
unix_peer(sk) = newsk
BUG: kernel NULL pointer dereference, address: 0000000000000080
RIP: 0010:unix_stream_bpf_update_proto+0xa0/0x1b0
Call Trace:
sock_map_link+0x564/0x8b0
sock_map_update_common+0x6e/0x340
sock_map_update_elem_sys+0x17d/0x240
__sys_bpf+0x26db/0x3250
__x64_sys_bpf+0x21/0x30
do_syscall_64+0x6b/0x3a0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Initial idea was to move peer assignment _before_ the sk_state update[1],
but that involved an additional memory barrier, and changing the hot path
was rejected.
Then a NULL check during proto update in unix_stream_bpf_update_proto() was
considered[2], but the follow-up discussion[3] focused on the root cause,
i.e. sockmap update taking a wrong lock. Or, more specifically, missing
unix_state_lock()[4].
In the end it was concluded that teaching sockmap about the af_unix locking
would be unnecessarily complex[5].
Complexity aside, since BPF_PROG_TYPE_SCHED_CLS and BPF_PROG_TYPE_SCHED_ACT
are allowed to update sockmaps, sock_map_update_elem() taking the unix
lock, as it is currently implemented in unix_state_lock():
spin_lock(&unix_sk(s)->lock), would be problematic. unix_state_lock() taken
in a process context, followed by a softirq-context TC BPF program
attempting to take the same spinlock -- deadlock[6].
This way we circled back to the peer check idea[2].
[1]: https://lore.kernel.org/netdev/ba5c50aa-1df4-40c2-ab33-a72022c5a32e@rbox.co/
[2]: https://lore.kernel.org/netdev/20240610174906.32921-1-kuniyu@amazon.com/
[3]: https://lore.kernel.org/netdev/7603c0e6-cd5b-452b-b710-73b64bd9de26@linux.dev/
[4]: https://lore.kernel.org/netdev/CAAVpQUA+8GL_j63CaKb8hbxoL21izD58yr1NvhOhU=j+35+3og@mail.gmail.com/
[5]: https://lore.kernel.org/bpf/CAAVpQUAHijOMext28Gi10dSLuMzGYh+jK61Ujn+fZ-wvcODR2A@mail.gmail.com/
[6]: https://lore.kernel.org/bpf/dd043c69-4d03-46fe-8325-8f97101435cf@linux.dev/
Summary of scenarios where af_unix/stream connect() may race a sockmap
update:
1. connect() vs. bpf(BPF_MAP_UPDATE_ELEM), i.e. sock_map_update_elem_sys()
Implemented NULL check is sufficient. Once assigned, socket peer won't
be released until socket fd is released. And that's not an issue because
sock_map_update_elem_sys() bumps fd refcnf.
2. connect() vs BPF program doing update
Update restricted per verifier.c:may_update_sockmap() to
BPF_PROG_TYPE_TRACING/BPF_TRACE_ITER
BPF_PROG_TYPE_SOCK_OPS (bpf_sock_map_update() only)
BPF_PROG_TYPE_SOCKET_FILTER
BPF_PROG_TYPE_SCHED_CLS
BPF_PROG_TYPE_SCHED_ACT
BPF_PROG_TYPE_XDP
BPF_PROG_TYPE_SK_REUSEPORT
BPF_PROG_TYPE_FLOW_DISSECTOR
BPF_PROG_TYPE_SK_LOOKUP
Plus one more race to consider:
CPU0 bpf CPU1 connect
-------- ------------
WRITE_ONCE(sk->sk_state, TCP_ESTABLISHED)
sock_map_sk_state_allowed(sk)
sock_hold(newsk)
smp_mb__after_atomic()
---truncated---
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Fix af_unix iter deadlock
bpf_iter_unix_seq_show() may deadlock when lock_sock_fast() takes the fast
path and the iter prog attempts to update a sockmap. Which ends up spinning
at sock_map_update_elem()'s bh_lock_sock():
WARNING: possible recursive locking detected
test_progs/1393 is trying to acquire lock:
ffff88811ec25f58 (slock-AF_UNIX){+...}-{3:3}, at: sock_map_update_elem+0xdb/0x1f0
but task is already holding lock:
ffff88811ec25f58 (slock-AF_UNIX){+...}-{3:3}, at: __lock_sock_fast+0x37/0xe0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(slock-AF_UNIX);
lock(slock-AF_UNIX);
*** DEADLOCK ***
May be due to missing lock nesting notation
4 locks held by test_progs/1393:
#0: ffff88814b59c790 (&p->lock){+.+.}-{4:4}, at: bpf_seq_read+0x59/0x10d0
#1: ffff88811ec25fd8 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: bpf_seq_read+0x42c/0x10d0
#2: ffff88811ec25f58 (slock-AF_UNIX){+...}-{3:3}, at: __lock_sock_fast+0x37/0xe0
#3: ffffffff85a6a7c0 (rcu_read_lock){....}-{1:3}, at: bpf_iter_run_prog+0x51d/0xb00
Call Trace:
dump_stack_lvl+0x5d/0x80
print_deadlock_bug.cold+0xc0/0xce
__lock_acquire+0x130f/0x2590
lock_acquire+0x14e/0x2b0
_raw_spin_lock+0x30/0x40
sock_map_update_elem+0xdb/0x1f0
bpf_prog_2d0075e5d9b721cd_dump_unix+0x55/0x4f4
bpf_iter_run_prog+0x5b9/0xb00
bpf_iter_unix_seq_show+0x1f7/0x2e0
bpf_seq_read+0x42c/0x10d0
vfs_read+0x171/0xb20
ksys_read+0xff/0x200
do_syscall_64+0x6b/0x3a0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix data loss caused by incorrect use of nat_entry flag
Data loss can occur when fsync is performed on a newly created file
(before any checkpoint has been written) concurrently with a checkpoint
operation. The scenario is as follows:
create & write & fsync 'file A' write checkpoint
- f2fs_do_sync_file // inline inode
- f2fs_write_inode // inode folio is dirty
- f2fs_write_checkpoint
- f2fs_flush_merged_writes
- f2fs_sync_node_pages
- f2fs_flush_nat_entries
- f2fs_fsync_node_pages // no dirty node
- f2fs_need_inode_block_update // return false
SPO and lost 'file A'
f2fs_flush_nat_entries() sets the IS_CHECKPOINTED and HAS_LAST_FSYNC
flags for the nat_entry, but this does not mean that the checkpoint has
actually completed successfully. However, f2fs_need_inode_block_update()
checks these flags and incorrectly assumes that the checkpoint has
finished.
The root cause is that the semantics of IS_CHECKPOINTED and
HAS_LAST_FSYNC are only guaranteed after the checkpoint write fully
completes.
This patch modifies f2fs_need_inode_block_update() to acquire the
sbi->node_write lock before reading the nat_entry flags, ensuring that
once IS_CHECKPOINTED and HAS_LAST_FSYNC are observed to be set, the
checkpoint operation has already completed.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-24
In the Linux kernel, the following vulnerability has been resolved:
f2fs: avoid reading already updated pages during GC
We found the following issue during fuzz testing:
page: refcount:3 mapcount:0 mapping:00000000b6e89c65 index:0x18b2dc pfn:0x161ba9
memcg:f8ffff800e269c00
aops:f2fs_meta_aops ino:2
flags: 0x52880000000080a9(locked|waiters|uptodate|lru|private|zone=1|kasantag=0x4a)
raw: 52880000000080a9 fffffffec6e17588 fffffffec0ccc088 a7ffff8067063618
raw: 000000000018b2dc 0000000000000009 00000003ffffffff f8ffff800e269c00
page dumped because: VM_BUG_ON_FOLIO(folio_test_uptodate(folio))
page_owner tracks the page as allocated
post_alloc_hook+0x58c/0x5ec
prep_new_page+0x34/0x284
get_page_from_freelist+0x2dcc/0x2e8c
__alloc_pages_noprof+0x280/0x76c
__folio_alloc_noprof+0x18/0xac
__filemap_get_folio+0x6bc/0xdc4
pagecache_get_page+0x3c/0x104
do_garbage_collect+0x5c78/0x77a4
f2fs_gc+0xd74/0x25f0
gc_thread_func+0xb28/0x2930
kthread+0x464/0x5d8
ret_from_fork+0x10/0x20
------------[ cut here ]------------
kernel BUG at mm/filemap.c:1563!
folio_end_read+0x140/0x168
f2fs_finish_read_bio+0x5c4/0xb80
f2fs_read_end_io+0x64c/0x708
bio_endio+0x85c/0x8c0
blk_update_request+0x690/0x127c
scsi_end_request+0x9c/0xb8c
scsi_io_completion+0xf0/0x250
scsi_finish_command+0x430/0x45c
scsi_complete+0x178/0x6d4
blk_mq_complete_request+0xcc/0x104
scsi_done_internal+0x214/0x454
scsi_done+0x24/0x34
which is similar to the problem reported by syzbot:
https://syzkaller.appspot.com/bug?extid=3686758660f980b402dc
This case is consistent with the description in commit 9bf1a3f
("f2fs: avoid GC causing encrypted file corrupted"):
Page 1 is moved from blkaddr A to blkaddr B by move_data_block, and after
being written it is marked as uptodate. Then, Page 1 is moved from blkaddr
B to blkaddr C, VM_BUG_ON_FOLIO was triggered in the endio initiated by
ra_data_block.
There is no need to read Page 1 again from blkaddr B, since it has already
been updated. Therefore, avoid initiating I/O in this case.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-06-24