Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
nfc: pn533: allocate rx skb before consuming bytes
pn532_receive_buf() reports the number of accepted bytes to the serdev
core. The current code consumes bytes into recv_skb and may already hand
a complete frame to pn533_recv_frame() before allocating a fresh receive
buffer.
If that alloc_skb() fails, the callback returns 0 even though it has
already consumed bytes, and it leaves recv_skb as NULL for the next
receive callback. That breaks the receive_buf() accounting contract and
can also lead to a NULL dereference on the next skb_put_u8().
Allocate the receive skb lazily before consuming the next byte instead.
If allocation fails, return the number of bytes already accepted.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
wifi: brcmsmac: Fix dma_free_coherent() size
dma_alloc_consistent() may change the size to align it. The new size is
saved in alloced.
Change the free size to match the allocation size.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
tipc: fix bc_ackers underflow on duplicate GRP_ACK_MSG
The GRP_ACK_MSG handler in tipc_group_proto_rcv() currently decrements
bc_ackers on every inbound group ACK, even when the same member has
already acknowledged the current broadcast round.
Because bc_ackers is a u16, a duplicate ACK received after the last
legitimate ACK wraps the counter to 65535. Once wrapped,
tipc_group_bc_cong() keeps reporting congestion and later group
broadcasts on the affected socket stay blocked until the group is
recreated.
Fix this by ignoring duplicate or stale ACKs before touching bc_acked or
bc_ackers. This makes repeated GRP_ACK_MSG handling idempotent and
prevents the underflow path.
CVSS Score
7.5
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
xfrm: hold dev ref until after transport_finish NF_HOOK
After async crypto completes, xfrm_input_resume() calls dev_put()
immediately on re-entry before the skb reaches transport_finish.
The skb->dev pointer is then used inside NF_HOOK and its okfn,
which can race with device teardown.
Remove the dev_put from the async resumption entry and instead
drop the reference after the NF_HOOK call in transport_finish,
using a saved device pointer since NF_HOOK may consume the skb.
This covers NF_DROP, NF_QUEUE and NF_STOLEN paths that skip
the okfn.
For non-transport exits (decaps, gro, drop) and secondary
async return points, release the reference inline when
async is set.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
idpf: fix PREEMPT_RT raw/bh spinlock nesting for async VC handling
Switch from using the completion's raw spinlock to a local lock in the
idpf_vc_xn struct. The conversion is safe because complete/_all() are
called outside the lock and there is no reason to share the completion
lock in the current logic. This avoids invalid wait context reported by
the kernel due to the async handler taking BH spinlock:
[ 805.726977] =============================
[ 805.726991] [ BUG: Invalid wait context ]
[ 805.727006] 7.0.0-rc2-net-devq-031026+ #28 Tainted: G S OE
[ 805.727026] -----------------------------
[ 805.727038] kworker/u261:0/572 is trying to lock:
[ 805.727051] ff190da6a8dbb6a0 (&vport_config->mac_filter_list_lock){+...}-{3:3}, at: idpf_mac_filter_async_handler+0xe9/0x260 [idpf]
[ 805.727099] other info that might help us debug this:
[ 805.727111] context-{5:5}
[ 805.727119] 3 locks held by kworker/u261:0/572:
[ 805.727132] #0: ff190da6db3e6148 ((wq_completion)idpf-0000:83:00.0-mbx){+.+.}-{0:0}, at: process_one_work+0x4b5/0x730
[ 805.727163] #1: ff3c6f0a6131fe50 ((work_completion)(&(&adapter->mbx_task)->work)){+.+.}-{0:0}, at: process_one_work+0x1e5/0x730
[ 805.727191] #2: ff190da765190020 (&x->wait#34){+.+.}-{2:2}, at: idpf_recv_mb_msg+0xc8/0x710 [idpf]
[ 805.727218] stack backtrace:
...
[ 805.727238] Workqueue: idpf-0000:83:00.0-mbx idpf_mbx_task [idpf]
[ 805.727247] Call Trace:
[ 805.727249] <TASK>
[ 805.727251] dump_stack_lvl+0x77/0xb0
[ 805.727259] __lock_acquire+0xb3b/0x2290
[ 805.727268] ? __irq_work_queue_local+0x59/0x130
[ 805.727275] lock_acquire+0xc6/0x2f0
[ 805.727277] ? idpf_mac_filter_async_handler+0xe9/0x260 [idpf]
[ 805.727284] ? _printk+0x5b/0x80
[ 805.727290] _raw_spin_lock_bh+0x38/0x50
[ 805.727298] ? idpf_mac_filter_async_handler+0xe9/0x260 [idpf]
[ 805.727303] idpf_mac_filter_async_handler+0xe9/0x260 [idpf]
[ 805.727310] idpf_recv_mb_msg+0x1c8/0x710 [idpf]
[ 805.727317] process_one_work+0x226/0x730
[ 805.727322] worker_thread+0x19e/0x340
[ 805.727325] ? __pfx_worker_thread+0x10/0x10
[ 805.727328] kthread+0xf4/0x130
[ 805.727333] ? __pfx_kthread+0x10/0x10
[ 805.727336] ret_from_fork+0x32c/0x410
[ 805.727345] ? __pfx_kthread+0x10/0x10
[ 805.727347] ret_from_fork_asm+0x1a/0x30
[ 805.727354] </TASK>
CVSS Score
5.5
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
mm: filemap: fix nr_pages calculation overflow in filemap_map_pages()
When running stress-ng on my Arm64 machine with v7.0-rc3 kernel, I
encountered some very strange crash issues showing up as "Bad page state":
"
[ 734.496287] BUG: Bad page state in process stress-ng-env pfn:415735fb
[ 734.496427] page: refcount:0 mapcount:1 mapping:0000000000000000 index:0x4cf316 pfn:0x415735fb
[ 734.496434] flags: 0x57fffe000000800(owner_2|node=1|zone=2|lastcpupid=0x3ffff)
[ 734.496439] raw: 057fffe000000800 0000000000000000 dead000000000122 0000000000000000
[ 734.496440] raw: 00000000004cf316 0000000000000000 0000000000000000 0000000000000000
[ 734.496442] page dumped because: nonzero mapcount
"
After analyzing this page’s state, it is hard to understand why the
mapcount is not 0 while the refcount is 0, since this page is not where
the issue first occurred. By enabling the CONFIG_DEBUG_VM config, I can
reproduce the crash as well and captured the first warning where the issue
appears:
"
[ 734.469226] page: refcount:33 mapcount:0 mapping:00000000bef2d187 index:0x81a0 pfn:0x415735c0
[ 734.469304] head: order:5 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
[ 734.469315] memcg:ffff000807a8ec00
[ 734.469320] aops:ext4_da_aops ino:100b6f dentry name(?):"stress-ng-mmaptorture-9397-0-2736200540"
[ 734.469335] flags: 0x57fffe400000069(locked|uptodate|lru|head|node=1|zone=2|lastcpupid=0x3ffff)
......
[ 734.469364] page dumped because: VM_WARN_ON_FOLIO((_Generic((page + nr_pages - 1),
const struct page *: (const struct folio *)_compound_head(page + nr_pages - 1), struct page *:
(struct folio *)_compound_head(page + nr_pages - 1))) != folio)
[ 734.469390] ------------[ cut here ]------------
[ 734.469393] WARNING: ./include/linux/rmap.h:351 at folio_add_file_rmap_ptes+0x3b8/0x468,
CPU#90: stress-ng-mlock/9430
[ 734.469551] folio_add_file_rmap_ptes+0x3b8/0x468 (P)
[ 734.469555] set_pte_range+0xd8/0x2f8
[ 734.469566] filemap_map_folio_range+0x190/0x400
[ 734.469579] filemap_map_pages+0x348/0x638
[ 734.469583] do_fault_around+0x140/0x198
......
[ 734.469640] el0t_64_sync+0x184/0x188
"
The code that triggers the warning is: "VM_WARN_ON_FOLIO(page_folio(page +
nr_pages - 1) != folio, folio)", which indicates that set_pte_range()
tried to map beyond the large folio’s size.
By adding more debug information, I found that 'nr_pages' had overflowed
in filemap_map_pages(), causing set_pte_range() to establish mappings for
a range exceeding the folio size, potentially corrupting fields of pages
that do not belong to this folio (e.g., page->_mapcount).
After above analysis, I think the possible race is as follows:
CPU 0 CPU 1
filemap_map_pages() ext4_setattr()
//get and lock folio with old inode->i_size
next_uptodate_folio()
.......
//shrink the inode->i_size
i_size_write(inode, attr->ia_size);
//calculate the end_pgoff with the new inode->i_size
file_end = DIV_ROUND_UP(i_size_read(mapping->host), PAGE_SIZE) - 1;
end_pgoff = min(end_pgoff, file_end);
......
//nr_pages can be overflowed, cause xas.xa_index > end_pgoff
end = folio_next_index(folio) - 1;
nr_pages = min(end, end_pgoff) - xas.xa_index + 1;
......
//map large folio
filemap_map_folio_range()
......
//truncate folios
truncate_pagecache(inode, inode->i_size);
To fix this issue, move the 'end_pgoff' calculation before
next_uptodate_folio(), so the retrieved folio stays consistent with the
file end to avoid
---truncated---
CVSS Score
7.8
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
net: stmmac: fix integer underflow in chain mode
The jumbo_frm() chain-mode implementation unconditionally computes
len = nopaged_len - bmax;
where nopaged_len = skb_headlen(skb) (linear bytes only) and bmax is
BUF_SIZE_8KiB or BUF_SIZE_2KiB. However, the caller stmmac_xmit()
decides to invoke jumbo_frm() based on skb->len (total length including
page fragments):
is_jumbo = stmmac_is_jumbo_frm(priv, skb->len, enh_desc);
When a packet has a small linear portion (nopaged_len <= bmax) but a
large total length due to page fragments (skb->len > bmax), the
subtraction wraps as an unsigned integer, producing a huge len value
(~0xFFFFxxxx). This causes the while (len != 0) loop to execute
hundreds of thousands of iterations, passing skb->data + bmax * i
pointers far beyond the skb buffer to dma_map_single(). On IOMMU-less
SoCs (the typical deployment for stmmac), this maps arbitrary kernel
memory to the DMA engine, constituting a kernel memory disclosure and
potential memory corruption from hardware.
Fix this by introducing a buf_len local variable clamped to
min(nopaged_len, bmax). Computing len = nopaged_len - buf_len is then
always safe: it is zero when the linear portion fits within a single
descriptor, causing the while (len != 0) loop to be skipped naturally,
and the fragment loop in stmmac_xmit() handles page fragments afterward.
CVSS Score
9.8
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
mmc: vub300: fix use-after-free on disconnect
The vub300 driver maintains an explicit reference count for the
controller and its driver data and the last reference can in theory be
dropped after the driver has been unbound.
This specifically means that the controller allocation must not be
device managed as that can lead to use-after-free.
Note that the lifetime is currently also incorrectly tied the parent USB
device rather than interface, which can lead to memory leaks if the
driver is unbound without its device being physically disconnected (e.g.
on probe deferral).
Fix both issues by reverting to non-managed allocation of the controller.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
mmc: vub300: fix NULL-deref on disconnect
Make sure to deregister the controller before dropping the reference to
the driver data on disconnect to avoid NULL-pointer dereferences or
use-after-free.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
mm/damon/stat: deallocate damon_call() failure leaking damon_ctx
damon_stat_start() always allocates the module's damon_ctx object
(damon_stat_context). Meanwhile, if damon_call() in the function fails,
the damon_ctx object is not deallocated. Hence, if the damon_call() is
failed, and the user writes Y to “enabled” again, the previously
allocated damon_ctx object is leaked.
This cannot simply be fixed by deallocating the damon_ctx object when
damon_call() fails. That's because damon_call() failure doesn't guarantee
the kdamond main function, which accesses the damon_ctx object, is
completely finished. In other words, if damon_stat_start() deallocates
the damon_ctx object after damon_call() failure, the not-yet-terminated
kdamond could access the freed memory (use-after-free).
Fix the leak while avoiding the use-after-free by keeping returning
damon_stat_start() without deallocating the damon_ctx object after
damon_call() failure, but deallocating it when the function is invoked
again and the kdamond is completely terminated. If the kdamond is not yet
terminated, simply return -EAGAIN, as the kdamond will soon be terminated.
The issue was discovered [1] by sashiko.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-04-24