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

vsock/virtio: Initialization of the dangling pointer occurring in vsk->trans

During loopback communication, a dangling pointer can be created in vsk->trans, potentially leading to a Use-After-Free condition. This issue is resolved by initializing vsk->trans to NULL.

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

ALSA: usb-audio: Fix out of bounds reads when finding clock sources

The current USB-audio driver code doesn't check bLength of each descriptor at traversing for clock descriptors. That is, when a device provides a bogus descriptor with a shorter bLength, the driver might hit out-of-bounds reads.

For addressing it, this patch adds sanity checks to the validator functions for the clock descriptor traversal. When the descriptor length is shorter than expected, it's skipped in the loop.

For the clock source and clock multiplier descriptors, we can just check bLength against the sizeof() of each descriptor type. OTOH, the clock selector descriptor of UAC2 and UAC3 has an array of bNrInPins elements and two more fields at its tail, hence those have to be checked in addition to the sizeof() check.

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:

kasan: avoid sleepable page allocation from atomic context

applytopterange() enters the lazy MMU mode and then invokes kasanpopulatevmallocpte() callback on each page table walk iteration. However, the callback can go into sleep when trying to allocate a single page, e.g. if an architecutre disables preemption on lazy MMU mode enter.

On s390 if make archenterlazymmumode() -> preemptenable() and archleavelazymmumode() -> preemptdisable(), such crash occurs:

[ 0.663336] BUG: sleeping function called from invalid context at ./include/linux/sched/mm.h:321 [ 0.663348] inatomic(): 1, irqsdisabled(): 0, nonblock: 0, pid: 2, name: kthreadd [ 0.663358] preemptcount: 1, expected: 0 [ 0.663366] RCU nest depth: 0, expected: 0 [ 0.663375] no locks held by kthreadd/2. [ 0.663383] Preemption disabled at: [ 0.663386] [<0002f3284cbb4eda>] applytopterange+0xfa/0x4a0 [ 0.663405] CPU: 0 UID: 0 PID: 2 Comm: kthreadd Not tainted 6.15.0-rc5-gcc-kasan-00043-gd76bb1ebb558-dirty #162 PREEMPT [ 0.663408] Hardware name: IBM 3931 A01 701 (KVM/Linux) [ 0.663409] Call Trace: [ 0.663410] [<0002f3284c385f58>] dumpstacklvl+0xe8/0x140 [ 0.663413] [<0002f3284c507b9e>] mightresched+0x66e/0x700 [ 0.663415] [<0002f3284cc4f6c0>] allocfrozenpagesnoprof+0x370/0x4b0 [ 0.663419] [<0002f3284ccc73c0>] allocpagesmpol+0x1a0/0x4a0 [ 0.663421] [<0002f3284ccc8518>] allocfrozenpagesnoprof+0x88/0xc0 [ 0.663424] [<0002f3284ccc8572>] allocpagesnoprof+0x22/0x120 [ 0.663427] [<0002f3284cc341ac>] getfreepagesnoprof+0x2c/0xc0 [ 0.663429] [<0002f3284cceba70>] kasanpopulatevmallocpte+0x50/0x120 [ 0.663433] [<0002f3284cbb4ef8>] applytopterange+0x118/0x4a0 [ 0.663435] [<0002f3284cbc7c14>] applytopmdrange+0x194/0x3e0 [ 0.663437] [<0002f3284cbc99be>] applytopagerange+0x2fe/0x7a0 [ 0.663440] [<0002f3284cbc9e88>] applytopagerange+0x28/0x40 [ 0.663442] [<0002f3284ccebf12>] kasanpopulatevmalloc+0x82/0xa0 [ 0.663445] [<0002f3284cc1578c>] allocvmaparea+0x34c/0xc10 [ 0.663448] [<0002f3284cc1c2a6>] getvmareanode+0x186/0x2a0 [ 0.663451] [<0002f3284cc1e696>] vmallocnoderangenoprof+0x116/0x310 [ 0.663454] [<0002f3284cc1d950>] vmallocnodenoprof+0xd0/0x110 [ 0.663457] [<0002f3284c454b88>] allocthreadstacknode+0xf8/0x330 [ 0.663460] [<0002f3284c458d56>] duptaskstruct+0x66/0x4d0 [ 0.663463] [<0002f3284c45be90>] copyprocess+0x280/0x4b90 [ 0.663465] [<0002f3284c460940>] kernelclone+0xd0/0x4b0 [ 0.663467] [<0002f3284c46115e>] kernelthread+0xbe/0xe0 [ 0.663469] [<0002f3284c4e440e>] kthreadd+0x50e/0x7f0 [ 0.663472] [<0002f3284c38c04a>] retfromfork+0x8a/0xf0 [ 0.663475] [<0002f3284ed57ff2>] retfromfork+0xa/0x38

Instead of allocating single pages per-PTE, bulk-allocate the shadow memory prior to applying kasanpopulatevmallocpte() callback on a page range.

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

media: dvbdev: prevent the risk of out of memory access

The dvbdev contains a static variable used to store dvb minors.

The behavior of it depends if CONFIGDVBDYNAMICMINORS is set or not. When not set, dvbregisterdevice() won't check for boundaries, as it will rely that a previous call to dvbregisteradapter() would already be enforcing it.

On a similar way, dvbdeviceopen() uses the assumption that the register functions already did the needed checks.

This can be fragile if some device ends using different calls. This also generate warnings on static check analysers like Coverity.

So, add explicit guards to prevent potential risk of OOM issues.

An issue was discovered in l2capsockrelease in net/bluetooth/l2capsock.c in the Linux kernel before 6.4.10. There is a use-after-free because the children of an sk are mishandled.

A remote denial of service vulnerability was found in the Linux kernel’s TIPC kernel module. The while loop in tipclinkxmit() hits an unknown state while attempting to parse SKBs, which are not in the queue. Sending two small UDP packets to a system with a UDP bearer results in the CPU utilization for the system to instantly spike to 100%, causing a denial of service condition.

A flaw in the Linux Kernel found. There are use-after-free vulnerabilities in drivers/media/rc/eneir.c of linux that allow attacker to crash linux kernel without any privilege by detaching rc device.

When the rc device is detaching, function eneremove() will be called. But the synchronizations in eneremove() are bad. The situations that may lead to race conditions are shown below.

Firstly, the rx receiver is disabled with enerxdisable() before rcunregisterdevice() in eneremove(), which means it can be enabled again if a process opens /dev/lirc0 between enerxdisable() and rcunregisterdevice().

(cleanup routine) | (open routine) eneremove() | enerxdisable(dev); | eneopen() | enerxenable(dev); //re-enable!

Secondly, the irqaction descriptor is freed by freeirq() before the rc device is unregistered, which means irqaction descriptor may be accessed again after it is deallocated.

(free routine) | (use routine) eneremove() | enerxenable() freeirq(dev->irq, ...); //FREE | enerxenablehw() | enewritereg(..., dev->irq << 1) //USE |

Thirdly, the timer can call enetxsample() that can write to the io ports, which means the io ports could be accessed again after they are deallocated by releaseregion().

(free routine) | (use routine) eneremove() | enetxsample() releaseregion(dev->hwio, ...); //FREE | enewritereg() | outb(..., dev->hwio + ENEIO) //USE

Fourthly, there is no function to cancel txsimtimer in eneremove(), the timer handler enetxirqsim() could race with eneremove(). As a result, the UAF bugs could happen, the process is shown below.

(free routine) | (use routine) | modtimer(&dev->txsimtimer, ..) eneremove() | (wait a time) kfree(dev) //FREE | enetxirqsim() | dev->hwlock //USE | enetxsample(dev) //USE

------------------------------------------

Reference: https://github.com/torvalds/linux/commit/29b0589a865b6f66d141d79b2dd1373e4e50fe17

An issue was discovered in flsetgeneveopt in net/sched/clsflower.c in the Linux kernel before 6.3.7. It allows an out-of-bounds write in the flower classifier code via TCAFLOWERKEYENCOPTSGENEVE packets. This may result in denial of service or privilege escalation.

A use-after-free vulnerability in the Linux kernel's afunix component can be exploited to achieve local privilege escalation.

The unixstreamsendpage() function tries to add data to the last skb in the peer's recv queue without locking the queue. Thus there is a race where unixstreamsendpage() could access an skb locklessly that is being released by garbage collection, resulting in use-after-free.

We recommend upgrading past commit 790c2f9d15b594350ae9bca7b236f2b1859de02c (or backported equivalents).

drm/dp: Fix OOB read when handling Post Cursor2 register

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

net: dsa: free routing table on probe failure

If complete = true in dsatreesetup(), it means that we are the last switch of the tree which is successfully probing, and we should be setting up all switches from our probe path.

After "complete" becomes true, dsatreesetupcpuports() or any subsequent function may fail. If that happens, the entire tree setup is in limbo: the first N-1 switches have successfully finished probing (doing nothing but having allocated persistent memory in the tree's dst->ports, and maybe dst->rtable), and switch N failed to probe, ending the tree setup process before anything is tangible from the user's PoV.

If switch N fails to probe, its memory (ports) will be freed and removed from dst->ports. However, the dst->rtable elements pointing to its ports, as created by dsalinktouch(), will remain there, and will lead to use-after-free if dereferenced.

If dsatreesetupswitches() returns -EPROBEDEFER, which is entirely possible because that is where ds->ops->setup() is, we get a kasan report like this:

================================================================== BUG: KASAN: slab-use-after-free in mv88e6xxxsetupupstreamport+0x240/0x568 Read of size 8 at addr ffff000004f56020 by task kworker/u8:3/42

Call trace: asanreportload8noabort+0x20/0x30 mv88e6xxxsetupupstreamport+0x240/0x568 mv88e6xxxsetup+0xebc/0x1eb0 dsaregisterswitch+0x1af4/0x2ae0 mv88e6xxxregisterswitch+0x1b8/0x2a8 mv88e6xxxprobe+0xc4c/0xf60 mdioprobe+0x78/0xb8 reallyprobe+0x2b8/0x5a8 driverprobedevice+0x164/0x298 driverprobedevice+0x78/0x258 deviceattachdriver+0x274/0x350

Allocated by task 42: kasankmalloc+0x84/0xa0 kmalloccachenoprof+0x298/0x490 dsaswitchtouchports+0x174/0x3d8 dsaregisterswitch+0x800/0x2ae0 mv88e6xxxregisterswitch+0x1b8/0x2a8 mv88e6xxxprobe+0xc4c/0xf60 mdioprobe+0x78/0xb8 reallyprobe+0x2b8/0x5a8 driverprobedevice+0x164/0x298 driverprobedevice+0x78/0x258 deviceattachdriver+0x274/0x350

Freed by task 42: kasanslabfree+0x48/0x68 kfree+0x138/0x418 dsaregisterswitch+0x2694/0x2ae0 mv88e6xxxregisterswitch+0x1b8/0x2a8 mv88e6xxxprobe+0xc4c/0xf60 mdioprobe+0x78/0xb8 reallyprobe+0x2b8/0x5a8 driverprobedevice+0x164/0x298 driverprobedevice+0x78/0x258 deviceattachdriver+0x274/0x350

The simplest way to fix the bug is to delete the routing table in its entirety. dsatreesetuproutingtable() has no problem in regenerating it even if we deleted links between ports other than those of switch N, because dsalinktouch() first checks whether the port pair already exists in dst->rtable, allocating if not.

The deletion of the routing table in its entirety already exists in dsatreeteardown(), so refactor that into a function that can also be called from the tree setup error path.

In my analysis of the commit to blame, it is the one which added dsalink elements to dst->rtable. Prior to that, each switch had its own ds->rtable which is freed when the switch fails to probe. But the tree is potentially persistent memory.

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

netfilter: flowtable: strictly check for maximum number of actions

The maximum number of flowtable hardware offload actions in IPv6 is:

ethernet mangling (4 payload actions, 2 for each ethernet address) SNAT (4 payload actions) DNAT (4 payload actions) Double VLAN (4 vlan actions, 2 for popping vlan, and 2 for pushing) for QinQ. Redirect (1 action)

Which makes 17, while the maximum is 16. But actct supports for tunnels actions too. Note that payload action operates at 32-bit word level, so mangling an IPv6 address takes 4 payload actions.

Update flowactionentrynext() calls to check for the maximum number of supported actions.

While at it, rise the maximum number of actions per flow from 16 to 24 so this works fine with IPv6 setups.

A flaw was found in the Linux kernel. This flaw allows an attacker to crash the Linux kernel by simulating amateur radio from the user space, resulting in a null-ptr-deref vulnerability and a use-after-free vulnerability.

drivers/usb/gadget/legacy/inode.c in the Linux kernel through 5.16.8 mishandles dev->buf release.

A flaw in the Linux Kernel found. A use-after-free vulnerability in the Linux kernel's net/sched: clsu32 component can be exploited to achieve local privilege escalation. If tcfchangeindev() fails, u32setparms() will immediately return an error after incrementing or decrementing the reference counter in tcfbindfilter(). If an attacker can control the reference counter and set it to zero, they can cause the reference to be freed, leading to a use-after-free vulnerability.

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=04c55383fa5689357bcdd2c8036725a55ed632bc

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

posix-cpu-timers: fix race between handleposixcputimers() and posixcputimerdel()

If an exiting non-autoreaping task has already passed exitnotify() and calls handleposixcputimers() from IRQ, it can be reaped by its parent or debugger right after unlocktasksighand().

If a concurrent posixcputimerdel() runs at that moment, it won't be able to detect timer->it.cpu.firing != 0: cputimertaskrcu() and/or locktasksighand() will fail.

Add the tsk->exitstate check into runposixcputimers() to fix this.

This fix is not needed if CONFIGPOSIXCPUTIMERSTASKWORK=y, because exittaskwork() is called before exitnotify(). But the check still makes sense, taskworkadd(&tsk->posixcputimerswork.work) will fail anyway in this case.

futex: Clear stale exiting pointer in futexlockpi() retry path

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

scsi: core: Wake up the error handler when final completions race against each other

The fragile ordering between marking commands completed or failed so that the error handler only wakes when the last running command completes or times out has race conditions. These race conditions can cause the SCSI layer to fail to wake the error handler, leaving I/O through the SCSI host stuck as the error state cannot advance.

First, there is an memory ordering issue within scsidechostbusy(). The write which clears SCMDSTATEINFLIGHT may be reordered with reads counting in scsihostbusy(). While the local CPU will see its own write, reordering can allow other CPUs in scsidechostbusy() or scsiehinchostfailed() to see a raised busy count, causing no CPU to see a host busy equal to the hostfailed count.

This race condition can be prevented with a memory barrier on the error path to force the write to be visible before counting host busy commands.

Second, there is a general ordering issue with scsiehinchostfailed(). By counting busy commands before incrementing hostfailed, it can race with a final command in scsidechostbusy(), such that scsidechostbusy() does not see hostfailed incremented but scsiehinchostfailed() counts busy commands before SCMDSTATEINFLIGHT is cleared by scsidechostbusy(), resulting in neither waking the error handler task.

This needs the call to scsihostbusy() to be moved after hostfailed is incremented to close the race condition.

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

SUNRPC: svcauthgss: avoid NULL deref on zero length gsstoken in gssreadproxyverf

A zero length gsstoken results in pages == 0 and intoken->pages[0] is NULL. The code unconditionally evaluates pageaddress(intoken->pages[0]) for the initial memcpy, which can dereference NULL even when the copy length is 0. Guard the first memcpy so it only runs when length > 0.

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

tcp: Clear tcpsk(sk)->fastopenrsk in tcpdisconnect().

syzbot reported the splat below where a socket had tcpsk(sk)->fastopenrsk in the TCPESTABLISHED state. [0]

syzbot reused the server-side TCP Fast Open socket as a new client before the TFO socket completes 3WHS:

1. accept() 2. connect(AFUNSPEC) 3. connect() to another destination

As of accept(), sk->skstate is TCPSYNRECV, and tcpdisconnect() changes it to TCPCLOSE and makes connect() possible, which restarts timers.

Since tcpdisconnect() forgot to clear tcpsk(sk)->fastopenrsk, the retransmit timer triggered the warning and the intended packet was not retransmitted.

Let's call reqskfastopenremove() in tcpdisconnect().

[0]: WARNING: CPU: 2 PID: 0 at net/ipv4/tcptimer.c:542 tcpretransmittimer (net/ipv4/tcptimer.c:542 (discriminator 7)) Modules linked in: CPU: 2 UID: 0 PID: 0 Comm: swapper/2 Not tainted 6.17.0-rc5-g201825fb4278 #62 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:tcpretransmittimer (net/ipv4/tcptimer.c:542 (discriminator 7)) Code: 41 55 41 54 55 53 48 8b af b8 08 00 00 48 89 fb 48 85 ed 0f 84 55 01 00 00 0f b6 47 12 3c 03 74 0c 0f b6 47 12 3c 04 74 04 90 <0f> 0b 90 48 8b 85 c0 00 00 00 48 89 ef 48 8b 40 30 e8 6a 4f 06 3e RSP: 0018:ffffc900002f8d40 EFLAGS: 00010293 RAX: 0000000000000002 RBX: ffff888106911400 RCX: 0000000000000017 RDX: 0000000002517619 RSI: ffffffff83764080 RDI: ffff888106911400 RBP: ffff888106d5c000 R08: 0000000000000001 R09: ffffc900002f8de8 R10: 00000000000000c2 R11: ffffc900002f8ff8 R12: ffff888106911540 R13: ffff888106911480 R14: ffff888106911840 R15: ffffc900002f8de0 FS: 0000000000000000(0000) GS:ffff88907b768000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8044d69d90 CR3: 0000000002c30003 CR4: 0000000000370ef0 Call Trace: <IRQ> tcpwritetimer (net/ipv4/tcptimer.c:738) calltimerfn (kernel/time/timer.c:1747) runtimers (kernel/time/timer.c:1799 kernel/time/timer.c:2372) timerexpireremote (kernel/time/timer.c:2385 kernel/time/timer.c:2376 kernel/time/timer.c:2135) tmigrhandleremoteup (kernel/time/timermigration.c:944 kernel/time/timermigration.c:1035) walkgroups.isra.0 (kernel/time/timermigration.c:533 (discriminator 1)) tmigrhandleremote (kernel/time/timermigration.c:1096) handlesoftirqs (./arch/x86/include/asm/jumplabel.h:36 ./include/trace/events/irq.h:142 kernel/softirq.c:580) irqexitrcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680 kernel/softirq.c:696) sysvecapictimerinterrupt (arch/x86/kernel/apic/apic.c:1050 (discriminator 35) arch/x86/kernel/apic/apic.c:1050 (discriminator 35)) </IRQ>

cgroup: split cgroupdestroywq into 3 workqueues

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

jbd2: prevent softlockup in jbd2logdocheckpoint()

Both jbd2logdocheckpoint() and jbd2journalshrinkcheckpointlist() periodically release jlistlock after processing a batch of buffers to avoid long hold times on the jlistlock. However, since both functions contend for jlistlock, the combined time spent waiting and processing can be significant.

jbd2journalshrinkcheckpointlist() explicitly calls condresched() when needresched() is true to avoid softlockups during prolonged operations. But jbd2logdocheckpoint() only exits its loop when needresched() is true, relying on potentially sleeping functions like flushbatch() or waitonbuffer() to trigger rescheduling. If those functions do not sleep, the kernel may hit a softlockup.

watchdog: BUG: soft lockup - CPU#3 stuck for 156s! [kworker/u129:2:373] CPU: 3 PID: 373 Comm: kworker/u129:2 Kdump: loaded Not tainted 6.6.0+ #10 Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.27 06/13/2017 Workqueue: writeback wbworkfn (flush-7:2) pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : nativequeuedspinlockslowpath+0x358/0x418 lr : jbd2logdocheckpoint+0x31c/0x438 [jbd2] Call trace: nativequeuedspinlockslowpath+0x358/0x418 jbd2logdocheckpoint+0x31c/0x438 [jbd2] jbd2logwaitforspace+0xfc/0x2f8 [jbd2] addtransactioncredits+0x3bc/0x418 [jbd2] startthishandle+0xf8/0x560 [jbd2] jbd2journalstart+0x118/0x228 [jbd2] ext4journalstartsb+0x110/0x188 [ext4] ext4dowritepages+0x3dc/0x740 [ext4] ext4writepages+0xa4/0x190 [ext4] dowritepages+0x94/0x228 writebacksingleinode+0x48/0x318 writebacksbinodes+0x204/0x590 writebackinodeswb+0x54/0xf8 wbwriteback+0x2cc/0x3d8 wbdowriteback+0x2e0/0x2f8 wbworkfn+0x80/0x2a8 processonework+0x178/0x3e8 workerthread+0x234/0x3b8 kthread+0xf0/0x108 retfromfork+0x10/0x20

So explicitly call condresched() in jbd2logdocheckpoint() to avoid softlockup.

fs: Prevent file descriptor table allocations exceeding INTMAX

fs/buffer: fix use-after-free when call bhread() helper

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

netfilter: ctnetlink: fix refcount leak on table dump

There is a reference count leak in ctnetlinkdumptable(): if (res < 0) { nfconntrackget(&ct->ctgeneral); // HERE cb->args[1] = (unsigned long)ct; ...

While its very unlikely, its possible that ct == last. If this happens, then the refcount of ct was already incremented. This 2nd increment is never undone.

This prevents the conntrack object from being released, which in turn keeps prevents cnet->count from dropping back to 0.

This will then block the netns dismantle (or conntrack rmmod) as nfconntrackcleanupnetlist() will wait forever.

This can be reproduced by running conntrackresize.sh selftest in a loop. It takes ~20 minutes for me on a preemptible kernel on average before I see a runaway kworker spinning in nfconntrackcleanupnetlist.

One fix would to change this to: if (res < 0) { if (ct != last) nfconntrackget(&ct->ctgeneral);

But this reference counting isn't needed in the first place. We can just store a cookie value instead.

A followup patch will do the same for ctnetlinkexpdumptable, it looks to me as if this has the same problem and like ctnetlinkdumptable, we only need a 'skip hint', not the actual object so we can apply the same cookie strategy there as well.

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

net: lan743x: Fix memleak issue when GSO enabled

Always map the skb to the LS descriptor. Previously skb was mapped to EXT descriptor when the number of fragments is zero with GSO enabled. Mapping the skb to EXT descriptor prevents it from being freed, leading to a memory leak

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

net: Fix null-ptr-deref by socklockinitclassandname() and rmmod.

When I ran the repro [0] and waited a few seconds, I observed two LOCKDEP splats: a warning immediately followed by a null-ptr-deref. [1]

Reproduction Steps:

1) Mount CIFS 2) Add an iptables rule to drop incoming FIN packets for CIFS 3) Unmount CIFS 4) Unload the CIFS module 5) Remove the iptables rule

At step 3), the CIFS module calls sockrelease() for the underlying TCP socket, and it returns quickly. However, the socket remains in FINWAIT1 because incoming FIN packets are dropped.

At this point, the module's refcnt is 0 while the socket is still alive, so the following rmmod command succeeds.

# ss -tan State Recv-Q Send-Q Local Address:Port Peer Address:Port FIN-WAIT-1 0 477 10.0.2.15:51062 10.0.0.137:445

# lsmod | grep cifs cifs 1159168 0

This highlights a discrepancy between the lifetime of the CIFS module and the underlying TCP socket. Even after CIFS calls sockrelease() and it returns, the TCP socket does not die immediately in order to close the connection gracefully.

While this is generally fine, it causes an issue with LOCKDEP because CIFS assigns a different lock class to the TCP socket's sk->sklock using socklockinitclassandname().

Once an incoming packet is processed for the socket or a timer fires, sk->sklock is acquired.

Then, LOCKDEP checks the lock context in checkwaitcontext(), where hlockclass() is called to retrieve the lock class. However, since the module has already been unloaded, hlockclass() logs a warning and returns NULL, triggering the null-ptr-deref.

If LOCKDEP is enabled, we must ensure that a module calling socklockinitclassandname() (CIFS, NFS, etc) cannot be unloaded while such a socket is still alive to prevent this issue.

Let's hold the module reference in socklockinitclassandname() and release it when the socket is freed in skprotfree().

Note that socklockinit() clears sk->skowner for svccreatesocket() that calls socklockinitclassandname() for a listening socket, which clones a socket by skclonelock() without GFPZERO.

[0]: CIFSSERVER="10.0.0.137" CIFSPATH="//${CIFSSERVER}/Users/Administrator/Desktop/CIFSTEST" DEV="enp0s3" CRED="/root/WindowsCredential.txt"

MNT=$(mktemp -d /tmp/XXXXXX) mount -t cifs ${CIFSPATH} ${MNT} -o vers=3.0,credentials=${CRED},cache=none,echointerval=1

iptables -A INPUT -s ${CIFSSERVER} -j DROP

for i in $(seq 10); do umount ${MNT} rmmod cifs sleep 1 done

rm -r ${MNT}

iptables -D INPUT -s ${CIFSSERVER} -j DROP

[1]: DEBUGLOCKSWARNON(1) WARNING: CPU: 10 PID: 0 at kernel/locking/lockdep.c:234 hlockclass (kernel/locking/lockdep.c:234 kernel/locking/lockdep.c:223) Modules linked in: cifsarc4 nlsucs2utils cifsmd4 [last unloaded: cifs] CPU: 10 UID: 0 PID: 0 Comm: swapper/10 Not tainted 6.14.0 #36 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:hlockclass (kernel/locking/lockdep.c:234 kernel/locking/lockdep.c:223) ... Call Trace: <IRQ> lockacquire (kernel/locking/lockdep.c:4853 kernel/locking/lockdep.c:5178) lockacquire (kernel/locking/lockdep.c:469 kernel/locking/lockdep.c:5853 kernel/locking/lockdep.c:5816) rawspinlocknested (kernel/locking/spinlock.c:379) tcpv4rcv (./include/linux/skbuff.h:1678 ./include/net/tcp.h:2547 net/ipv4/tcpipv4.c:2350) ...

BUG: kernel NULL pointer dereference, address: 00000000000000c4 PF: supervisor read access in kernel mode PF: errorcode(0x0000) - not-present page PGD 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 10 UID: 0 PID: 0 Comm: swapper/10 Tainted: G W 6.14.0 #36 Tainted: [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:lockacquire (kernel/ ---truncated---

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

thermal: int340x: Add NULL check for adev

Not all devices have an ACPI companion fwnode, so adev might be NULL. This is similar to the commit cd2fd6eab480 ("platform/x86: int3472: Check for adev == NULL").

Add a check for adev not being set and return -ENODEV in that case to avoid a possible NULL pointer deref in int3402thermalprobe().

Note, under the same directory, int3400thermalprobe() has such a check.

[ rjw: Subject edit, added Fixes: ]

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

ipv6: Fix memleak of nhcpcpurthoutput in fibchecknhv6gw().

fibchecknhv6gw() expects that fib6nhinit() cleans up everything when it fails.

Commit 7dd73168e273 ("ipv6: Always allocate pcpu memory in a fib6nh") moved fibnhcommoninit() before allocpercpugfp() within fib6nhinit() but forgot to add cleanup for fib6nh->nhcommon.nhcpcpurthoutput in case it fails to allocate fib6nh->rt6ipcpu, resulting in memleak.

Let's call fibnhcommonrelease() and clear nhcpcpurthoutput in the error path.

Note that we can remove the fib6nhrelease() call in nhcreateipv6() later in net-next.git.