linux-stable.git, branch v6.12.86

Linux 6.12.86

2026-05-07T04:09:48+00:00

Link: https://lore.kernel.org/r/20260504135130.169210693@linuxfoundation.org
Tested-by: Brett A C Sheffield 
Tested-by: Peter Schneider 
Tested-by: Florian Fainelli 
Tested-by: Salvatore Bonaccorso 
Tested-by: Francesco Dolcini 
Tested-by: Ron Economos 
Tested-by: Miguel Ojeda 
Tested-by: Mark Brown 
Tested-by: Shuah Khan 
Tested-by: Barry K. Nathan 
Signed-off-by: Greg Kroah-Hartman

netfilter: reject zero shift in nft_bitwise

2026-05-07T04:09:48+00:00

commit fe11e5c40817b84abaa5d83bfb6586d8412bfd07 upstream.

Reject zero shift operands for nft_bitwise left and right shift
expressions during initialization.

The carry propagation logic computes the carry from the adjacent 32-bit
word using BITS_PER_TYPE(u32) - shift. A zero shift operand turns this
into a 32-bit shift, which is undefined behaviour.

Reject zero shift operands in the control plane, alongside the existing
check for values greater than or equal to 32, so malformed rules never
reach the packet path.

Fixes: 567d746b55bc ("netfilter: bitwise: add support for shifts.")
Cc: stable@kernel.org
Reported-by: Yuan Tan 
Reported-by: Yifan Wu 
Reported-by: Juefei Pu 
Reported-by: Xin Liu 
Signed-off-by: Kai Ma 
Signed-off-by: Ren Wei 
Reviewed-by: Fernando Fernandez Mancera 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

net: ipv6: fix NOREF dst use in seg6 and rpl lwtunnels

2026-05-07T04:09:48+00:00

commit f9c52a6ba9780bd27e0bf4c044fd91c13c778b6e upstream.

seg6_input_core() and rpl_input() call ip6_route_input() which sets a
NOREF dst on the skb, then pass it to dst_cache_set_ip6() invoking
dst_hold() unconditionally.
On PREEMPT_RT, ksoftirqd is preemptible and a higher-priority task can
release the underlying pcpu_rt between the lookup and the caching
through a concurrent FIB lookup on a shared nexthop.
Simplified race sequence:

  ksoftirqd/X                       higher-prio task (same CPU X)
  -----------                       --------------------------------
  seg6_input_core(,skb)/rpl_input(skb)
    dst_cache_get()
      -> miss
    ip6_route_input(skb)
      -> ip6_pol_route(,skb,flags)
         [RT6_LOOKUP_F_DST_NOREF in flags]
        -> FIB lookup resolves fib6_nh
           [nhid=N route]
        -> rt6_make_pcpu_route()
           [creates pcpu_rt, refcount=1]
             pcpu_rt->sernum = fib6_sernum
             [fib6_sernum=W]
           -> cmpxchg(fib6_nh.rt6i_pcpu,
                      NULL, pcpu_rt)
              [slot was empty, store succeeds]
      -> skb_dst_set_noref(skb, dst)
         [dst is pcpu_rt, refcount still 1]

                                    rt_genid_bump_ipv6()
                                      -> bumps fib6_sernum
                                         [fib6_sernum from W to Z]
                                    ip6_route_output()
                                      -> ip6_pol_route()
                                        -> FIB lookup resolves fib6_nh
                                           [nhid=N]
                                        -> rt6_get_pcpu_route()
                                             pcpu_rt->sernum != fib6_sernum
                                             [W <> Z, stale]
                                          -> prev = xchg(rt6i_pcpu, NULL)
                                          -> dst_release(prev)
                                             [prev is pcpu_rt,
                                              refcount 1->0, dead]

    dst = skb_dst(skb)
    [dst is the dead pcpu_rt]
    dst_cache_set_ip6(dst)
      -> dst_hold() on dead dst
      -> WARN / use-after-free

For the race to occur, ksoftirqd must be preemptible (PREEMPT_RT without
PREEMPT_RT_NEEDS_BH_LOCK) and a concurrent task must be able to release
the pcpu_rt. Shared nexthop objects provide such a path, as two routes
pointing to the same nhid share the same fib6_nh and its rt6i_pcpu
entry.

Fix seg6_input_core() and rpl_input() by calling skb_dst_force() after
ip6_route_input() to force the NOREF dst into a refcounted one before
caching.
The output path is not affected as ip6_route_output() already returns a
refcounted dst.

Fixes: af4a2209b134 ("ipv6: sr: use dst_cache in seg6_input")
Fixes: a7a29f9c361f ("net: ipv6: add rpl sr tunnel")
Cc: stable@vger.kernel.org
Signed-off-by: Andrea Mayer 
Reviewed-by: Simon Horman 
Reviewed-by: Justin Iurman 
Link: https://patch.msgid.link/20260421094735.20997-1-andrea.mayer@uniroma2.it
Signed-off-by: Paolo Abeni 
Signed-off-by: Greg Kroah-Hartman

ALSA: caiaq: fix usb_dev refcount leak on probe failure

2026-05-07T04:09:48+00:00

commit 7a5f1cd22d47f8ca4b760b6334378ae42c1bd24b upstream.

create_card() takes a reference on the USB device with usb_get_dev()
and stores the matching usb_put_dev() in card_free(), which is
installed as the snd_card's ->private_free destructor.

However, ->private_free is only assigned near the end of init_card(),
after several failure points (usb_set_interface(), EP type checks,
usb_submit_urb(), the EP1_CMD_GET_DEVICE_INFO exchange, and its
timeout). When any of those fail, init_card() returns an error to
snd_probe(), which calls snd_card_free(card). Because ->private_free
is still NULL, card_free() never runs, the usb_get_dev() reference
is not dropped, and the struct usb_device leaks along with its
descriptor allocations and device_private.

syzbot reproduces this with a malformed UAC3 device whose only valid
altsetting is 0; init_card()'s usb_set_interface(usb_dev, 0, 1) call
fails with -EIO and triggers the leak.

Move the ->private_free assignment into create_card(), immediately
after usb_get_dev(), so that every error path reaching snd_card_free()
balances the reference. card_free()'s callees (snd_usb_caiaq_input_free,
free_urbs, kfree) already tolerate the partially-initialized state
because the chip private area is zero-initialized by snd_card_new().

Fixes: 80bb50e2d459 ("ALSA: caiaq: take a reference on the USB device in create_card()")
Reported-by: syzbot+2afd7e71155c7e241560@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=2afd7e71155c7e241560
Tested-by: syzbot+2afd7e71155c7e241560@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Deepanshu Kartikey 
Link: https://patch.msgid.link/20260426001934.70813-1-kartikey406@gmail.com
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

drm/amdgpu: fix zero-size GDS range init on RDNA4

2026-05-07T04:09:47+00:00

commit 095a8b0ad3c3b5cdc3850d961adb8a8f735220bb upstream.

RDNA4 (GFX 12) hardware removes the GDS, GWS, and OA on-chip memory
resources. The gfx_v12_0 initialisation code correctly leaves
adev->gds.gds_size, adev->gds.gws_size, and adev->gds.oa_size at
zero to reflect this.

amdgpu_ttm_init() unconditionally calls amdgpu_ttm_init_on_chip() for
each of these resources regardless of size. When the size is zero,
amdgpu_ttm_init_on_chip() forwards the call to ttm_range_man_init(),
which calls drm_mm_init(mm, 0, 0). drm_mm_init() immediately fires
DRM_MM_BUG_ON(start + size <= start) -- trivially true when size is
zero -- crashing the kernel during modprobe of amdgpu on an RX 9070 XT.

Guard against this by returning 0 early from
amdgpu_ttm_init_on_chip() when size_in_page is zero. This skips TTM
resource manager registration for hardware resources that are absent,
without affecting any other GPU type.

DRM_MM_BUG_ON() only asserts if CONFIG_DRM_DEBUG_MM is enabled in
the kernel config.  This is apparently rarely enabled as these chips
have been in the market for over a year and this issue was only reported
now.

Link: https://lore.kernel.org/all/bug-221376-2300@https.bugzilla.kernel.org%2F/
Link: https://bugzilla.kernel.org/show_bug.cgi?id=221376
Oops-Analysis: http://oops.fenrus.org/reports/bugzilla.korg/221376/report.html
Assisted-by: GitHub Copilot:Claude Sonnet 4.6 linux-kernel-oops-x86.
Signed-off-by: Arjan van de Ven 
Cc: Alex Deucher 
Cc: "Christian König" 
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Alex Deucher 
(cherry picked from commit 5719ce5865279cad4fd5f01011fe037168503f2d)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

ipv6: rpl: reserve mac_len headroom when recompressed SRH grows

2026-05-07T04:09:47+00:00

commit 9e6bf146b55999a095bb14f73a843942456d1adc upstream.

ipv6_rpl_srh_rcv() decompresses an RFC 6554 Source Routing Header, swaps
the next segment into ipv6_hdr->daddr, recompresses, then pulls the old
header and pushes the new one plus the IPv6 header back.  The
recompressed header can be larger than the received one when the swap
reduces the common-prefix length the segments share with daddr (CmprI=0,
CmprE>0, seg[0][0] != daddr[0] gives the maximum +8 bytes).

pskb_expand_head() was gated on segments_left == 0, so on earlier
segments the push consumed unchecked headroom.  Once skb_push() leaves
fewer than skb->mac_len bytes in front of data,
skb_mac_header_rebuild()'s call to:

	skb_set_mac_header(skb, -skb->mac_len);

will store (data - head) - mac_len into the u16 mac_header field, which
wraps to ~65530, and the following memmove() writes mac_len bytes ~64KiB
past skb->head.

A single AF_INET6/SOCK_RAW/IPV6_HDRINCL packet over lo with a two
segment type-3 SRH (CmprI=0, CmprE=15) reaches headroom 8 after one
pass; KASAN reports a 14-byte OOB write in ipv6_rthdr_rcv.

Fix this by expanding the head whenever the remaining room is less than
the push size plus mac_len, and request that much extra so the rebuilt
MAC header fits afterwards.

Fixes: 8610c7c6e3bd ("net: ipv6: add support for rpl sr exthdr")
Cc: stable 
Reported-by: Anthropic
Signed-off-by: Greg Kroah-Hartman 
Link: https://patch.msgid.link/2026042133-gout-unvented-1bd9@gregkh
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

rxrpc: Fix rxrpc_input_call_event() to only unshare DATA packets

2026-05-07T04:09:47+00:00

commit 55b2984c96c37f909bbfe8851f13152693951382 upstream.

Fix rxrpc_input_call_event() to only unshare DATA packets and not ACK,
ABORT, etc..

And with that, rxrpc_input_packet() doesn't need to take a pointer to the
pointer to the packet, so change that to just a pointer.

Fixes: 1f2740150f90 ("rxrpc: Fix potential UAF after skb_unshare() failure")
Closes: https://sashiko.dev/#/patchset/20260422161438.2593376-4-dhowells@redhat.com
Signed-off-by: David Howells 
cc: Marc Dionne 
cc: Jeffrey Altman 
cc: Simon Horman 
cc: linux-afs@lists.infradead.org
cc: stable@kernel.org
Link: https://patch.msgid.link/20260423200909.3049438-2-dhowells@redhat.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

ALSA: caiaq: Don't abort when no input device is available

2026-05-07T04:09:47+00:00

commit b32ae47a2b0a1fb4bd4942242847966d9b178222 upstream.

The previous fix to handle the error from setup_card() caused a
regression for the models that have no dedicated input device;
snd_usb_caiaq_input_init() just returns -EINVAL, and we treat it as a
fatal error although it should be ignored.

As a regression fix, change the error code to -ENODEV, and ignore this
error in the callee, to continue probing.

Fixes: 28abd224db4a ("ALSA: caiaq: Handle probe errors properly")
Cc: 
Link: https://bugzilla.kernel.org/show_bug.cgi?id=221423
Link: https://patch.msgid.link/20260427145642.6637-1-tiwai@suse.de
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: caiaq: Fix potentially leftover ep1_in_urb at error path

2026-05-07T04:09:47+00:00

commit 0a7b5221b5b51cc798fcfc3be00d02eade149d69 upstream.

The previous fix for handling the error from setup_card() missed that
an internal URB cdev->ep1_in_urb might have been already submitted
beforehand.  In the normal case, this URB gets killed at the
disconnection, but in the error path, we didn't do it, hence there can
be a potential leak.

Fix it in the error path for setup_card(), too.

Fixes: 28abd224db4a ("ALSA: caiaq: Handle probe errors properly")
Cc: 
Link: https://patch.msgid.link/20260427123819.890185-1-tiwai@suse.de
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

driver core: Add kernel-doc for DEV_FLAG_COUNT enum value

2026-05-07T04:09:47+00:00

commit 5b484311507b5d403c1f7a45f6aa3778549e268b upstream.

Even though nobody should use this value (except when declaring the
"flags" bitmap), kernel-doc still gets upset that it's not documented.
It reports:

  WARNING: ../include/linux/device.h:519
  Enum value 'DEV_FLAG_COUNT' not described in enum 'struct_device_flags'

Add the description of DEV_FLAG_COUNT.

Fixes: a2225b6e834a ("driver core: Don't let a device probe until it's ready")
Reported-by: Randy Dunlap 
Closes: https://lore.kernel.org/f318cd43-81fd-48b9-abf7-92af85f12f91@infradead.org
Signed-off-by: Douglas Anderson 
Tested-by: Randy Dunlap 
Reviewed-by: Randy Dunlap 
Link: https://patch.msgid.link/20260413195910.1.I23aca74fe2d3636a47df196a80920fecb2643220@changeid
Signed-off-by: Danilo Krummrich 
Signed-off-by: Greg Kroah-Hartman