In the Linux kernel, the following vulnerability has been resolved:

ALSA: usb-audio: Fix potential out-of-bound accesses for Extigy and Mbox devices

A bogus device can provide a bNumConfigurations value that exceeds the initial value used in usbgetconfiguration for allocating dev->config.

This can lead to out-of-bounds accesses later, e.g. in usbdestroyconfiguration.

In the Linux kernel, the following vulnerability has been resolved:

module: Fix kernel panic when a symbol stshndx is out of bounds

The module loader doesn't check for bounds of the ELF section index in simplifysymbols():

for (i = 1; i < symsec->shsize / sizeof(ElfSym); i++) { const char name = info->strtab + sym[i].stname;

switch (sym[i].stshndx) { case SHNCOMMON:

[...]

default: / Divert to percpu allocation if a percpu var. / if (sym[i].stshndx == info->index.pcpu) secbase = (unsigned long)modpercpu(mod); else / HERE --> / secbase = info->sechdrs[sym[i].stshndx].shaddr; sym[i].stvalue += secbase; break; } }

A symbol with an out-of-bounds stshndx value, for example 0xffff (known as SHNXINDEX or SHNHIRESERVE), may cause a kernel panic:

BUG: unable to handle page fault for address: ... RIP: 0010:simplifysymbols+0x2b2/0x480 ... Kernel panic - not syncing: Fatal exception

This can happen when module ELF is legitimately using SHNXINDEX or when it is corrupted.

Add a bounds check in simplifysymbols() to validate that stshndx is within the valid range before using it.

This issue was discovered due to a bug in llvm-objcopy, see relevant discussion for details [1].

[1] https://lore.kernel.org/linux-modules/20251224005752.201911-1-ihor.solodrai@linux.dev/

fbdev: Fix doregisterframebuffer to prevent null-ptr-deref in fbvideomodetovar

ax25: Remove broken autobind

In the Linux kernel, the following vulnerability has been resolved:

The ftdisio driver (usb/serial/ftdisio.c) in Linux kernel 2.6.x up to 2.6.17, and possibly later versions, allows local users to cause a denial of service (memory consumption) by writing more data to the serial port than the hardware can handle, which causes the data to be queued.

In the Linux kernel, the following vulnerability has been resolved:

serial: core: fix infinite loop in handletx() for PORTUNKNOWN

uartwriteroom() and uartwrite() behave inconsistently when xmitbuf is NULL (which happens for PORTUNKNOWN ports that were never properly initialized):

- uartwriteroom() returns kfifoavail() which can be > 0 - uartwrite() checks xmitbuf and returns 0 if NULL

This inconsistency causes an infinite loop in drivers that rely on ttywriteroom() to determine if they can write:

while (ttywriteroom(tty) > 0) { written = tty->ops->write(...); // written is always 0, loop never exits }

For example, caifserial's handletx() enters an infinite loop when used with PORTUNKNOWN serial ports, causing system hangs.

Fix by making uartwriteroom() also check xmitbuf and return 0 if it's NULL, consistent with uartwrite().

Reproducer: https://gist.github.com/mrpre/d9a694cc0e19828ee3bc3b37983fde13

8021q: delete cleared egress QoS mappings

In the Linux kernel, the following vulnerability has been resolved:

Input: lkkbd - disable pending work before freeing device

lkkbdinterrupt() schedules lk->tq via schedulework(), and the work handler lkkbdreinit() dereferences the lkkbd structure and its serio/inputdev fields.

lkkbddisconnect() and error paths in lkkbdconnect() free the lkkbd structure without preventing the reinit work from being queued again until serioclose() returns. This can allow the work handler to run after the structure has been freed, leading to a potential use-after-free.

Use disableworksync() instead of cancelworksync() to ensure the reinit work cannot be re-queued, and call it both in lkkbddisconnect() and in lkkbdconnect() error paths after serioopen().

In the Linux kernel, the following vulnerability has been resolved:

USB: serial: ioti: fix heap overflow in getmanufinfo()

getmanufinfo() reads le16tocpu(romdesc->Size) bytes from the device I2C EEPROM into a buffer allocated with kmallocobj(), which is sizeof(struct edgetimanufdescriptor) = 10 bytes.

The Size field comes from the device and is only validated (in checki2cimage()) to make sure the descriptor fits within TIMAXI2CSIZE (16384 bytes), not against the destination buffer size. A malicious USB device can therefore set Size to any value up to 16377, causing a heap overflow of up to 16367 bytes when plugged into a host running this driver.

validcsum() is called after readrom() and also iterates buffer[0..Size-1], compounding the out-of-bounds access.

Fix by rejecting descriptors with unexpected length before calling readrom().

[ johan: amend commit message; also check for short descriptors ]

In the Linux kernel, the following vulnerability has been resolved:

net/sched: Enforce that teql can only be used as root qdisc

Design intent of teql is that it is only supposed to be used as root qdisc. We need to check for that constraint.

Although not important, I will describe the scenario that unearthed this issue for the curious.

GangMin Kim <km.kim1503@gmail.com> managed to concot a scenario as follows:

ROOT qdisc 1:0 (QFQ) ├── class 1:1 (weight=15, lmax=16384) netem with delay 6.4s └── class 1:2 (weight=1, lmax=1514) teql

GangMin sends a packet which is enqueued to 1:1 (netem). Any invocation of dequeue by QFQ from this class will not return a packet until after 6.4s. In the meantime, a second packet is sent and it lands on 1:2. teql's enqueue will return success and this will activate class 1:2. Main issue is that teql only updates the parent visible qlen (sch->q.qlen) at dequeue. Since QFQ will only call dequeue if peek succeeds (and teql's peek always returns NULL), dequeue will never be called and thus the qlen will remain as 0. With that in mind, when GangMin updates 1:2's lmax value, the qfqchangeclass calls qfqdeactrmfromagg. Since the child qdisc's qlen was not incremented, qfq fails to deactivate the class, but still frees its pointers from the aggregate. So when the first packet is rescheduled after 6.4 seconds (netem's delay), a dangling pointer is accessed causing GangMin's causing a UAF.

In the Linux kernel, the following vulnerability has been resolved:

net: afkey: zero aligned sockaddr tail in PFKEY exports

PFKEY export paths use pfkeysockaddrsize() when reserving sockaddr payload space, so IPv6 addresses occupy 32 bytes on the wire. However, pfkeysockaddrfill() initializes only the first 28 bytes of struct sockaddrin6, leaving the final 4 aligned bytes uninitialized.

Not every PFKEY message is affected. The state and policy dump builders already zero the whole message buffer before filling the sockaddr payloads. Keep the fix to the export paths that still append aligned sockaddr payloads with plain skbput():

- SADBACQUIRE - SADBXNATTNEWMAPPING - SADBXMIGRATE

Fix those paths by clearing only the aligned sockaddr tail after pfkeysockaddrfill().

In the Linux kernel, the following vulnerability has been resolved:

ax25: fix use-after-free bugs caused by ax25dsdeltimer

In the Linux kernel, the following vulnerability has been resolved:

posix-cpu-timers: Fix pid refcount leak in docpunanosleep() error path

In docpunanosleep(), posixcputimercreate() takes a pid reference via getpid() and stores it in timer.it.cpu.pid. If the subsequent posixcputimerset() call fails, the function returns immediately without calling posixcputimerdel() to release the pid reference, causing a leak.

Fix it by calling posixcputimerdel() before the unlock-and-return on the error path, consistent with the other exit paths in the same function.

In the Linux kernel, the following vulnerability has been resolved:

netfilter: ebtables: zero chainstack array

sashiko reports: looking at ebtables table translation, could a sparse cpupossiblemask lead to an uninitialized pointer free?

If cpupossiblemask is sparse (for example, CPU 0 and CPU 2 are possible, but CPU 1 is not), the allocation loop skips CPU 1. If vmallocnode() fails at CPU 2, the cleanup loop will blindly decrement and call vfree() on newinfo->chainstack[1].

Not a real-world bug, such allocation isn't expected to fail in the first place.

In the Linux kernel, the following vulnerability has been resolved:

isofs: bound Rock Ridge symlink components to the SL record

getsymlinkchunk() and the SL handling in parserockridgeinodeinternal() walk the variable-length components of a Rock Ridge "SL" (symbolic link) record. Each component is a two-byte header (flags, len) followed by len bytes of text, so it occupies slp->len + 2 bytes. Both loops read slp->len and advance to the next component, and getsymlinkchunk() additionally does memcpy(rpnt, slp->text, slp->len), but neither checks that the component lies within the SL record before dereferencing it.

A crafted SL record whose component declares a len that runs past the record (rr->len) therefore triggers an out-of-bounds read of up to 255 bytes. When the record sits at the tail of its backing buffer - for example a small kmalloc()ed continuation block reached through a CE record - the read crosses the allocation; getsymlinkchunk() then copies the out-of-bounds bytes into the symlink body returned to user space by readlink(), disclosing adjacent kernel memory.

ISO 9660 images are routinely mounted from untrusted removable media - desktop environments auto-mount them (e.g. via udisks2) without CAPSYSADMIN - so the record contents are attacker-controlled.

Reject any component that does not fit in the remaining record bytes before using it. In getsymlinkchunk() return NULL, like the existing output-buffer (plimit) checks, so a malformed record makes readlink() fail with -EIO rather than silently returning a truncated target; in parserockridgeinodeinternal() stop the inode-size walk.

In the Linux kernel, the following vulnerability has been resolved:

netfilter: ebtables: terminate table name before findtablelock()

updatecounters() and compatupdatecounters() forward a user-supplied 32-byte table name to findtablelock() without NUL-terminating it. On a lookup miss, findinlistlock() calls trythenrequestmodule(..., "%s%s", "ebtable", name), and vsnprintf() reads past the name field and the stack object until it hits a zero byte.

BUG: KASAN: stack-out-of-bounds in string (lib/vsprintf.c:648 lib/vsprintf.c:730) Read of size 1 at addr ffff8880119dfb20 by task exploit/147 Call Trace: ... string (lib/vsprintf.c:648 lib/vsprintf.c:730) vsnprintf (lib/vsprintf.c:2945) requestmodule (kernel/module/kmod.c:150) doupdatecounters.isra.0 (net/bridge/netfilter/ebtables.c:371 net/bridge/netfilter/ebtables.c:380) updatecounters (net/bridge/netfilter/ebtables.c:1440) doebtsetctl (net/bridge/netfilter/ebtables.c:2573) nfsetsockopt (net/netfilter/nfsockopt.c:101) ipsetsockopt (net/ipv4/ipsockglue.c:1424) rawsetsockopt (net/ipv4/raw.c:847) syssetsockopt (net/socket.c:2393) ...

compatdoreplace() shares the same unterminated name via compatcopyebtreplacefromuser(); terminate it there too so all findtablelock() callers behave alike. The other callers already terminate the name after the copy.

In the Linux kernel, the following vulnerability has been resolved:

ipv4: restrict IPOPTSSRR and IPOPTLSRR options

This patch restricts setting Loose Source and Record Route (LSRR) and Strict Source and Record Route (SSRR) IP options to users with CAPNETRAW capability.

This prevents unprivileged applications from forcing packets to route through attacker-controlled nodes to leak TCP ISN and possibly other protocol information.

While LSRR and SSRR are commonly filtered in many network environments, they may still be supported and forwarded along some network paths.

RFC 7126 (Recommendations on Filtering of IPv4 Packets Containing IPv4 Options) recommend to drop these options in 4.3 and 4.4.

In the Linux kernel, the following vulnerability has been resolved:

tcp: restrict SOATTACHFILTER to priv users

This patch restricts the use of SOATTACHFILTER (cBPF) on TCP sockets to users with CAPNETADMIN capability.

This blocks potential side-channel attack where an unprivileged application attaches a filter to leak TCP sequence/acknowledgment numbers.

In the Linux kernel, the following vulnerability has been resolved:

fs/fcntl: fix SOFTIRQ-unsafe lock order in fasync signaling

A SOFTIRQ-safe to SOFTIRQ-unsafe lock order deadlock can occur in sendsigio() and sendsigurg() when a process group receives a signal.

When FASYNC is configured for a process group (PIDTYPEPGID), both functions use readlock(&tasklistlock) to traverse the task list. However, they are frequently called from softirq context: - sendsigio() via inputinjectevent -> killfasync - sendsigurg() via tcpcheckurg -> sksendsigurg (NETRXSOFTIRQ)

The deadlock is caused by the rwlock writer fairness mechanism: 1. CPU 0 (process context) holds readlock(&tasklistlock) in dowait(). 2. CPU 1 (process context) attempts writelock(&tasklistlock) in fork() or exit() and spins, which blocks all new readers. 3. CPU 0 is interrupted by a softirq (e.g., TCP URG packet reception). 4. The softirq calls sendsigurg() and attempts to acquire readlock(&tasklistlock), deadlocking because CPU 1 is waiting.

Since PID hashing and doeachpidtask() traversals are already RCU-protected, the readlock on tasklistlock is no longer strictly required for safe traversal. Fix this by replacing tasklistlock with rcureadlock(), aligning the process group signaling path with the single-PID path. This also mitigates a potential remote denial of service vector via TCP URG packets.

Lockdep splat: ===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected [...] Chain exists of: &dev->eventlock --> &fowner->lock --> tasklistlock

Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(tasklistlock); localirqdisable(); lock(&dev->eventlock); lock(&fowner->lock); <Interrupt> lock(&dev->eventlock);

DEADLOCK

In the Linux kernel, the following vulnerability has been resolved:

net: add proper RCU protection to /proc/net/ptype

Yin Fengwei reported an RCU stall in ptypeseqshow() and provided a patch.

Real issue is that ptypeseqnext() and ptypeseqshow() violate RCU rules.

ptypeseqshow() runs under rcureadlock(), and reads pt->dev to get device name without any barrier.

At the same time, concurrent writers can remove a packettype structure (which is correctly freed after an RCU grace period) and clear pt->dev without an RCU grace period.

Define ptypeiterstate to carry a dev pointer along seqnetprivate:

struct ptypeiterstate { struct seqnetprivate p; struct netdevice dev; // added in this patch };

We need to record the device pointer in ptypegetidx() and ptypeseqnext() so that ptypeseqshow() is safe against concurrent pt->dev changes.

We also need to add full RCU protection in ptypeseqnext(). (Missing READONCE() when reading list.next values)

Many thanks to Dong Chenchen for providing a repro.

In the Linux kernel, the following vulnerability has been resolved:

net/x25: Fix potential double free of skb

When allocskb fails in x25queuerxframe it calls kfreeskb(skb) at line 48 and returns 1 (error). This error propagates back through the call chain:

x25queuerxframe returns 1 | v x25state3machine receives the return value 1 and takes the else branch at line 278, setting queued=0 and returning 0 | v x25processrxframe returns queued=0 | v x25backlogrcv at line 452 sees queued=0 and calls kfreeskb(skb) again

This would free the same skb twice. Looking at x25backlogrcv:

net/x25/x25in.c:x25backlogrcv() { ... queued = x25processrxframe(sk, skb); ... if (!queued) kfreeskb(skb); }

In the Linux kernel, the following vulnerability has been resolved:

netfilter: ip6trt: reject oversized addrnr in rtmt6check()

Reject rt match rules whose addrnr exceeds IP6TRTHOPS.

rtmt6() expects addrnr to stay within the bounds of rtinfo->addrs[]. Validate addrnr during rule installation so malformed rules are rejected before the match logic can use an out-of-range value.

In the Linux kernel, the following vulnerability has been resolved:

xfrm: clear trailing padding in buildpolexpire()

buildexpire() clears the trailing padding bytes of struct xfrmuserexpire after setting the hard field via memsetafter(), but the analogous function buildpolexpire() does not do this for struct xfrmuserpolexpire.

The padding bytes after the u8 hard field are left uninitialized from the heap allocation, and are then sent to userspace via netlink multicast to XFRMNLGRPEXPIRE listeners, leaking kernel heap memory contents.

Add the missing memsetafter() call, matching buildexpire().

In the Linux kernel, the following vulnerability has been resolved:

net/sched: schhfsc: fix divide-by-zero in rtscmin()

m2sm() converts a u32 slope to a u64 scaled value. For large inputs (e.g. m1=4000000000), the result can reach 2^32. rtscmin() stores the difference of two such u64 values in a u32 variable dsm and uses it as a divisor. When the difference is exactly 2^32 the truncation yields zero, causing a divide-by-zero oops in the concave-curve intersection path:

Oops: divide error: 0000 RIP: 0010:rtscmin (net/sched/schhfsc.c:601) Call Trace: inited (net/sched/schhfsc.c:629) hfscenqueue (net/sched/schhfsc.c:1569) [...]

Widen dsm to u64 and replace dodiv() with div64u64() so the full difference is preserved.

In the Linux kernel, the following vulnerability has been resolved:

net/x25: Fix overflow when accumulating packets

Add a check to ensure that x25sock.fraglen does not overflow.

The fraglen also needs to be resetted when purging fragmentqueue in x25clearqueues().

In the Linux kernel, the following vulnerability has been resolved:

nfsd: fix heap overflow in NFSv4.0 LOCK replay cache

The NFSv4.0 replay cache uses a fixed 112-byte inline buffer (rpibuf[NFSD4REPLAYISIZE]) to store encoded operation responses. This size was calculated based on OPEN responses and does not account for LOCK denied responses, which include the conflicting lock owner as a variable-length field up to 1024 bytes (NFS4OPAQUELIMIT).

When a LOCK operation is denied due to a conflict with an existing lock that has a large owner, nfsd4encodeoperation() copies the full encoded response into the undersized replay buffer via readbytesfromxdrbuf() with no bounds check. This results in a slab-out-of-bounds write of up to 944 bytes past the end of the buffer, corrupting adjacent heap memory.

This can be triggered remotely by an unauthenticated attacker with two cooperating NFSv4.0 clients: one sets a lock with a large owner string, then the other requests a conflicting lock to provoke the denial.

We could fix this by increasing NFSD4REPLAYISIZE to allow for a full opaque, but that would increase the size of every stateowner, when most lockowners are not that large.

Instead, fix this by checking the encoded response length against NFSD4REPLAYISIZE before copying into the replay buffer. If the response is too large, set rpbuflen to 0 to skip caching the replay payload. The status is still cached, and the client already received the correct response on the original request.

In the Linux kernel, the following vulnerability has been resolved:

mtd: Avoid boot crash in RedBoot partition table parser

Given CONFIGFORTIFYSOURCE=y and a recent compiler, commit 439a1bcac648 ("fortify: Use builtindynamicobjectsize() when available") produces the warning below and an oops.

Searching for RedBoot partition table in 50000000.flash at offset 0x7e0000 ------------[ cut here ]------------ WARNING: lib/stringhelpers.c:1035 at 0xc029e04c, CPU#0: swapper/0/1 memcmp: detected buffer overflow: 15 byte read of buffer size 14 Modules linked in: CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.19.0 #1 NONE

As Kees said, "'names' is pointing to the final 'namelen' many bytes of the allocation ... 'namelen' could be basically any length at all. This fortify warning looks legit to me -- this code used to be reading beyond the end of the allocation."

Since the size of the dynamic allocation is calculated with strlen() we can use strcmp() instead of memcmp() and remain within bounds.

In the Linux kernel, the following vulnerability has been resolved:

net: usb: pegasus: validate USB endpoints

The pegasus driver should validate that the device it is probing has the proper number and types of USB endpoints it is expecting before it binds to it. If a malicious device were to not have the same urbs the driver will crash later on when it blindly accesses these endpoints.