<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/include, branch v5.15.220</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v5.15.220</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v5.15.220'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2026-09-02T12:27:28+00:00</updated>
<entry>
<title>usb: gadget: f_tcm: keep port count until LUN teardown completes</title>
<updated>2026-09-02T12:27:28+00:00</updated>
<author>
<name>Shuangpeng Bai</name>
<email>shuangpeng.kernel@gmail.com</email>
</author>
<published>2026-08-07T06:07:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=c1f359d9a5efed458946063de65ddbeaacc4f165'/>
<id>urn:sha1:c1f359d9a5efed458946063de65ddbeaacc4f165</id>
<content type='text'>
commit c39d0916da47d94909391876c9e5bd429ea7b1b9 upstream.

tcm_usbg_drop_nexus() permits session removal once tpg_port_count
reaches zero. However, usbg_port_unlink() currently decrements that
count from the fabric_pre_unlink() callback, before core_dev_del_lun()
waits for active se_lun references to drain.

If removal of the last LUN races a nexus removal, the latter can observe
a zero port count and call target_remove_session(). This frees
sess_cmd_map while an in-flight struct usbg_cmd, including its work item,
can still be accessed.

Overlapping the last-LUN unlink with nexus removal reproduces this
lifetime violation as a DEBUG_OBJECTS "free active" warning for
usbg_cmd_work, followed by a target-core BUG/Oops.

The generic target-core unlink path has no callback after
core_dev_del_lun() completes. Add an optional fabric_post_unlink()
callback and use it for the f_tcm port count. The count now remains
nonzero until core_dev_del_lun() has finished draining active LUN
references, preventing nexus removal from freeing the session during
command completion.

Fixes: c52661d60f63 ("usb-gadget: Initial merge of target module for UASP + BOT")
Cc: stable@vger.kernel.org
Signed-off-by: Shuangpeng Bai &lt;shuangpeng.kernel@gmail.com&gt;
Link: https://patch.msgid.link/20260807060733.3186624-1-shuangpeng.kernel@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>HID: input: read battery capacity from its actual report offset</title>
<updated>2026-09-02T12:27:28+00:00</updated>
<author>
<name>Jose Villaseñor Montfort</name>
<email>pepemontfort@gmail.com</email>
</author>
<published>2026-08-27T04:40:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=91f1ccb6b2e4efcef7a7d04bb0aa5255abf6b542'/>
<id>urn:sha1:91f1ccb6b2e4efcef7a7d04bb0aa5255abf6b542</id>
<content type='text'>
[ Upstream commit d07644524b6511b622ee7b0e2e68c9ee43d522a4 ]

hidinput_query_battery_capacity() assumes the state-of-charge value is
the first byte following the report ID (buf[1]) and ignores where the
battery field actually sits within the report.

An Apple Magic Trackpad 2 precedes the AbsoluteStateOfCharge byte with a
byte of status flags in its battery reports, so this query returns the
flags byte instead of the charge level.

The device happens to make that easy to observe, because it exposes the
same cell twice: its report descriptor declares AbsoluteStateOfCharge in
two reports (0x90 and 0x9b), so hidinput_setup_battery() registers two
power supplies. Only the first one is refreshed by hid-magicmouse -- it
uses hid_get_battery(), which returns the first battery of the list --
and that refresh goes through the report event path, which parses the
field correctly. Nothing ever reports the second one, so every read of
its capacity takes the query path above. On a USB-C Magic Trackpad over
USB, on an unpatched 7.1.5:

  hid-&lt;serial&gt;-battery-144 = 100%  (Charging)      &lt;- report event path
  hid-&lt;serial&gt;-battery-155 =   3%  (Discharging)   &lt;- query path

Both are the same physical battery. A raw HIDIOCGINPUT of the two
reports at that same moment:

  report 0x90 -&gt; [90 03 64]
  report 0x9b -&gt; [9b 03 64 64 00 00 10 00 00 00 00 00 00 00]
                     ^flags ^SoC = 0x64 = 100%

The device answers correctly in both cases; only the offset the kernel
reads the capacity from is wrong. 0x03 is the flags byte (present,
charging), reported as "3%".

Bluetooth takes the same query path for its capacity, where the trackpad
reported a bogus near-constant ~4% -- 0b100, the FullyCharged flag --
regardless of the real charge.

Store the battery field's offset within the report at setup time and use
it when querying, so the capacity is read from its real position. The
report event path already parses the field correctly through the HID
core; only the explicit GET_REPORT query was wrong.

Devices whose capacity field is the first field in the report have a
report_offset of 0 and are unaffected (buf[1 + 0] == buf[1]).

Fixes: 581c4484769e ("HID: input: map digitizer battery usage")
Cc: stable@vger.kernel.org
Signed-off-by: Jose Villaseñor Montfort &lt;pepemontfort@gmail.com&gt;
Reviewed-by: Alec Hall &lt;signshop.alec@gmail.com&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.com&gt;
[ Adapted `bat-&gt;report_offset` and other `struct hid_battery` accessors to the flat `dev-&gt;battery_*` fields on `struct hid_device` and replaced `__free(kfree)` with manual `kfree(buf)` calls. ]
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>nvme: rename CDR/MORE/DNR to NVME_STATUS_*</title>
<updated>2026-09-02T12:27:27+00:00</updated>
<author>
<name>Weiwen Hu</name>
<email>huweiwen@linux.alibaba.com</email>
</author>
<published>2026-08-26T17:14:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=87372cf6f3dac43ae5158b6f5f5f1d78329e5ad5'/>
<id>urn:sha1:87372cf6f3dac43ae5158b6f5f5f1d78329e5ad5</id>
<content type='text'>
[ Upstream commit dd0b0a4a2c5d7209457dc172997d1243ad269cfa ]

CDR/MORE/DNR fields are not belonging to SC in the NVMe spec, rename
them to NVME_STATUS_* to avoid confusion.

Signed-off-by: Weiwen Hu &lt;huweiwen@linux.alibaba.com&gt;
Reviewed-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Reviewed-by: Chaitanya Kulkarni &lt;kch@nvidia.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Keith Busch &lt;kbusch@kernel.org&gt;
Stable-dep-of: 4a3f00262a04 ("nvmet-tcp: bound SGL data length before allocating command buffers")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>kcov: fix data corruption and race conditions on PREEMPT_RT</title>
<updated>2026-09-02T12:27:27+00:00</updated>
<author>
<name>Tetsuo Handa</name>
<email>penguin-kernel@I-love.SAKURA.ne.jp</email>
</author>
<published>2026-08-25T19:48:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=8ed3ddf23d39bf5338406bd9f8863d44748cf6ce'/>
<id>urn:sha1:8ed3ddf23d39bf5338406bd9f8863d44748cf6ce</id>
<content type='text'>
[ Upstream commit 2eed77fdcb0cc48e8eccb2bcd4b7f2c6d650e84c ]

syzbot is reporting KCOV state corruption on PREEMPT_RT kernels, for the
temporary storage used for saving/restoring remote KCOV state is currently
allocated as the per-CPU area.

On PREEMPT_RT kernels, softirq handlers run as preemptible task threads
(e.g., ksoftirqd). If a softirq context preempts a task running a remote
KCOV session, it safely saves the task's state into the per-CPU area.
However, if that softirq thread is subsequently preempted by a higher-
priority softirq thread on the same CPU, the second softirq will overwrite
the same per-CPU area, permanently destroying the original task's KCOV
state.

Fix this data corruption by moving the temporary storage from the per-CPU
area to the per-thread area. Since each softirq thread now owns its own
task context, nested softirq preemption no longer causes data overwrites.

Note that while the temporary storage is now on a per-thread basis, the
per-CPU kcov_percpu_data.lock must be retained, for we need to ensure that
kcov_remote_start() and kcov_remote_stop() operate atomically without
racing against asynchronous interrupts that manipulate the current task's
KCOV state.

It is likely that GFP_KERNEL allocation by vmalloc_node() in kcov_init()
has already called panic() before returning NULL, for there will be no
OOM-killable userspace processes when __init function of built-in module
runs. But this patch also fixes crashing the kernel when vmalloc_node()
in kcov_init() returned NULL, for kcov_init() left per-CPU irq_area == NULL
but kcov_remote_start() depends on per-CPU irq_area != NULL, resulting in

  (1) doing vmalloc() in kcov_remote_start() despite !in_task() context

  (2) out-of-array-bounds access if (1) succeeded but
      kcov-&gt;remote_size &lt; CONFIG_KCOV_IRQ_AREA_SIZE

  (3) always leak memory allocated by (1), eventually killing all
      OOM-killable userspace processes

problems.

Link: https://lore.kernel.org/43552d09-2ce2-4b19-b0d3-a2d1ab952145@I-love.SAKURA.ne.jp
Reported-by: syzbot+3f51ad7ac3ae57a6fdcc@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=3f51ad7ac3ae57a6fdcc
Reported-by: syzbot+47cf95ca1f9dcca872c8@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=47cf95ca1f9dcca872c8
Reported-by: syzbot+8a173e13208949931dc7@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=8a173e13208949931dc7
Reported-by: syzbot+90984d3713722683112e@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=90984d3713722683112e
Analyzed-by: AI Mode in Google Search (no mail address)
Fixes: 5ff3b30ab57d ("kcov: collect coverage from interrupts")
Signed-off-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Reviewed-by: Alexander Potapenko &lt;glider@google.com&gt;
Cc: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Cc: Andrey Konovalov &lt;andreyknvl@gmail.com&gt;
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: Clark Williams &lt;williams@redhat.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Marco Elver &lt;elver@google.com&gt;
Cc: Mark Brown &lt;broonie@kernel.org&gt;
Cc: Roman Gushchin &lt;roman.gushchin@linux.dev&gt;
Cc: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
[ Adjusted the `kcov_init()` deletion context to plain `vmalloc()` since 5.15 lacks the `vmalloc_node()`/`cpu_to_node()` conversion. ]
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>ipv4: igmp: Fix potential UAF in igmp_gq_start_timer()</title>
<updated>2026-09-02T12:27:26+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2026-07-05T18:17:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=d107b4c4f8274763b7ea5ab05d45cef78e4b81ba'/>
<id>urn:sha1:d107b4c4f8274763b7ea5ab05d45cef78e4b81ba</id>
<content type='text'>
commit 7b19c0f81ed1fdaec6bc522569be367199a9edf3 upstream.

A race condition exists between device teardown (inetdev_destroy) and
incoming IGMP query processing (igmp_rcv), leading to a Use-After-Free
in the IGMP timer callback.

During device destruction, inetdev_destroy() drops the primary reference
to in_device, which can drop its refcount to 0. The actual freeing of
in_device memory is deferred via RCU (using call_rcu()).

Concurrently, igmp_rcv() runs under RCU read lock and obtains the
in_device pointer. Because the memory is RCU-protected, CPU-0 can safely
dereference in_device even if its refcount has hit 0.

However, if CPU-0 calls igmp_gq_start_timer() and re-arms the timer, it
attempts to acquire a reference using in_dev_hold(). This increments the
refcount from 0 to 1, triggering a "refcount_t: addition on 0" warning.
Since the in_device memory is still scheduled to be freed after the RCU
grace period (as the free callback does not check the refcount again),
the device is freed while the timer is still armed. When the timer
expires, it accesses the freed memory, causing a kernel panic.

Fix this by using refcount_inc_not_zero() (via a new helper
in_dev_hold_safe()) to prevent acquiring a reference if the device is
already being destroyed. If the refcount is 0, we do not arm the timer.

A similar issue in IPv6 MLD is fixed in a subsequent patch.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Zero Day Initiative &lt;zdi-disclosures@trendmicro.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Link: https://patch.msgid.link/20260705181756.963063-2-edumazet@google.com
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
[Denis Arefev: adapted for 5.10/5.15: keep prandom_u32(),
get_random_u32_below() not used here]
Signed-off-by: Denis Arefev &lt;arefev@swemel.ru&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>can: use skb hash instead of private variable in headroom</title>
<updated>2026-08-27T12:28:22+00:00</updated>
<author>
<name>Oliver Hartkopp</name>
<email>socketcan@hartkopp.net</email>
</author>
<published>2026-08-25T12:27:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=db6735e84bb13a3c3104594d6414bdaf7ae1a468'/>
<id>urn:sha1:db6735e84bb13a3c3104594d6414bdaf7ae1a468</id>
<content type='text'>
commit d4fb6514ff8ed6912a71294e6b66a5d59ee88007 upstream.

The can_skb_priv::skbcnt variable is used to identify CAN skbs in the RX
path analogue to the skb-&gt;hash.

As the skb hash is not filled in CAN skbs move the private skbcnt value to
skb-&gt;hash and set skb-&gt;sw_hash accordingly. The skb-&gt;hash is a value used
for RPS to identify skbs. Use it as intended.

Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://patch.msgid.link/20260201-can_skb_ext-v8-1-3635d790fe8b@hartkopp.net
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>KVM: Rename mmu_notifier_* to mmu_invalidate_*</title>
<updated>2026-08-27T12:28:21+00:00</updated>
<author>
<name>Chao Peng</name>
<email>chao.p.peng@linux.intel.com</email>
</author>
<published>2026-08-23T13:07:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=29c0039ea120e868598bee792aa3464523cf1ba3'/>
<id>urn:sha1:29c0039ea120e868598bee792aa3464523cf1ba3</id>
<content type='text'>
[ Upstream commit 20ec3ebd707c77fb9b11b37193449193d4649f33 ]

The motivation of this renaming is to make these variables and related
helper functions less mmu_notifier bound and can also be used for non
mmu_notifier based page invalidation. mmu_invalidate_* was chosen to
better describe the purpose of 'invalidating' a page that those
variables are used for.

  - mmu_notifier_seq/range_start/range_end are renamed to
    mmu_invalidate_seq/range_start/range_end.

  - mmu_notifier_retry{_hva} helper functions are renamed to
    mmu_invalidate_retry{_hva}.

  - mmu_notifier_count is renamed to mmu_invalidate_in_progress to
    avoid confusion with mn_active_invalidate_count.

  - While here, also update kvm_inc/dec_notifier_count() to
    kvm_mmu_invalidate_begin/end() to match the change for
    mmu_notifier_count.

No functional change intended.

Signed-off-by: Chao Peng &lt;chao.p.peng@linux.intel.com&gt;
Message-Id: &lt;20220816125322.1110439-3-chao.p.peng@linux.intel.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Stable-dep-of: 2abd5287f083 ("KVM: x86: Check for invalid/obsolete root *after* making MMU pages available")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Kenta Akagi &lt;k@mgml.me&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>net/sched: reject overly deep qdisc hierarchies</title>
<updated>2026-08-27T12:28:19+00:00</updated>
<author>
<name>Zijie Huang</name>
<email>milkory@outlook.com</email>
</author>
<published>2026-08-21T14:50:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=a627d36c2a94e18c8c105ae68008786dfd85592e'/>
<id>urn:sha1:a627d36c2a94e18c8c105ae68008786dfd85592e</id>
<content type='text'>
[ Upstream commit dedd34b0f2310e28c5f6d4875cfbf4b7ed821c01 ]

Deep qdisc hierarchies can lead to excessive recursion in qdisc tree
walkers and exhaust the kernel stack. The existing loop check does not
cover the create-and-graft path, so a hierarchy can still be extended by
creating a new child qdisc below an already deep parent.

Store the hierarchy depth in struct Qdisc and update it when qdiscs are
grafted. Reject new child qdiscs once the parent is already at the maximum
allowed depth.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Suggested-by: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Reported-by: Vega &lt;vega@nebusec.ai&gt;
Assisted-by: Codex:gpt-5.4
Signed-off-by: Zijie Huang &lt;milkory@outlook.com&gt;
Signed-off-by: Ren Wei &lt;enjou1224z@gmail.com&gt;
Reviewed-by: Victor Nogueira &lt;victor@mojatatu.com&gt;
Link: https://patch.msgid.link/1e9ab39597423fd5d13cfaaf52279b8ee3d9fc3c.1785434373.git.milkory@outlook.com
Acked-by: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
[ Dropped the `extack` argument from the `notify_and_destroy()` context line to match 5.15's 6-parameter version. ]
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>packet: use consistent hard_header_len in non-ring send paths</title>
<updated>2026-08-27T12:28:19+00:00</updated>
<author>
<name>Qihang Tang</name>
<email>q.h.hack.winter@gmail.com</email>
</author>
<published>2026-08-21T14:50:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=78a47127e33c340bc6d38dcc4552a094b4f5cc77'/>
<id>urn:sha1:78a47127e33c340bc6d38dcc4552a094b4f5cc77</id>
<content type='text'>
[ Upstream commit 03390aa32e669cc4ecd7d34108e2e1afc13d689d ]

packet_snd() reads dev-&gt;hard_header_len multiple times while allocating
and constructing an skb. Device reconfiguration can change this value
concurrently, for example through bonding device type changes.

For SOCK_RAW, packet_snd() can save a larger value in reserve and later
allocate headroom using a smaller value. Moving skb-&gt;data back by reserve
then places it before skb-&gt;head, and the following copy from userspace can
attempt an out-of-bounds write.

packet_sendmsg_spkt() has the same issue because it calculates its
reservation and header offset from separate reads before dropping the RCU
read lock to allocate the skb.

Add LL_RESERVED_SPACE_EX() for callers that already saved a header length.
Read hard_header_len once in packet_snd() and use it for allocation and
construction. In packet_sendmsg_spkt(), preserve the allocation-time value
through the device lookup retry.

The separate SOCK_DGRAM consistency problem between hard_header_len and
header_ops-&gt;create is not addressed here.

Fixes: b84bbaf7a6c8 ("packet: in packet_snd start writing at link layer allocation")
Cc: stable@vger.kernel.org
Signed-off-by: Qihang Tang &lt;q.h.hack.winter@gmail.com&gt;
Reviewed-by: Willem de Bruijn &lt;willemb@google.com&gt;
Link: https://patch.msgid.link/20260805125729.19220-3-q.h.hack.winter@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Stable-dep-of: 21b5953e7494 ("packet: use consistent hard_header_len in TX_RING send path")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>PCI: host-generic: Fix NULL pointer dereference on 32-bit CAM systems</title>
<updated>2026-08-27T12:28:18+00:00</updated>
<author>
<name>Steffen Persvold</name>
<email>spersvold@gmail.com</email>
</author>
<published>2026-07-09T12:24:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=5e52eb0290f66ba0732956dcb1e365b5ca3c5108'/>
<id>urn:sha1:5e52eb0290f66ba0732956dcb1e365b5ca3c5108</id>
<content type='text'>
commit 008cb88edb41f3c7c8e0ed763ff9f26719830984 upstream.

On 32-bit systems the config space is too large to ioremap in one go, so
pci_ecam_create() maps each bus segment separately and relies on the
-&gt;add_bus callback (pci_ecam_add_bus) to populate the per-bus mapping in
cfg-&gt;winp[]. pci_ecam_map_bus() then uses that mapping as the base for
every config access.

The generic ECAM ops (pci_generic_ecam_ops) already provide the -&gt;add_bus
and -&gt;remove_bus callbacks, but the CAM (legacy) ops in pci-host-generic.c
do not. As a result, on a 32-bit host using "pci-host-cam-generic" the
per-bus mapping is never set up and the first config read dereferences a
NULL base, crashing during bus enumeration:

 Unable to handle kernel NULL pointer dereference at virtual address 00000800
 Oops [#1]
 CPU: 0 PID: 1 Comm: swapper Not tainted 6.9.7+ #43
 Hardware name: Digilent Nexys-Video-A7 RV32 (DT)
 epc : pci_generic_config_read+0x40/0xb0
  ra : pci_generic_config_read+0x2c/0xb0
 [&lt;c038db9c&gt;] pci_generic_config_read+0x40/0xb0
 [&lt;c038da04&gt;] pci_bus_read_config_dword+0x50/0xb0
 [&lt;c0391e94&gt;] pci_bus_generic_read_dev_vendor_id+0x3c/0x1ec
 [&lt;c039245c&gt;] pci_scan_single_device+0xa4/0x11c
 [&lt;c0392570&gt;] pci_scan_slot+0x9c/0x23c
 [&lt;c039388c&gt;] pci_scan_child_bus_extend+0x58/0x2f4
 [&lt;c0393db0&gt;] pci_scan_root_bus_bridge+0x64/0xe8
 [&lt;c0393e54&gt;] pci_host_probe+0x20/0xc8
 [&lt;c03bc6f4&gt;] pci_host_common_probe+0x144/0x1e4

Fix this by giving the CAM ops the same -&gt;add_bus/-&gt;remove_bus callbacks.
Since pci_ecam_add_bus() and pci_ecam_remove_bus() are static to ecam.c,
move the CAM ops definition there as pci_generic_cam_ops (mirroring
pci_generic_ecam_ops) and export it for pci-host-generic.c to reference.

Fixes: 8fe55ef23387 ("PCI: Dynamically map ECAM regions")
Signed-off-by: Steffen Persvold &lt;spersvold@gmail.com&gt;
[mani: removed timestamp from log]
Signed-off-by: Manivannan Sadhasivam &lt;mani@kernel.org&gt;
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260709122446.3151899-1-spersvold@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
