<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/char, branch v6.6.148</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>ipmi: fix refcount leak in i_ipmi_request()</title>
<updated>2026-08-03T09:15:39+00:00</updated>
<author>
<name>Wentao Liang</name>
<email>vulab@iscas.ac.cn</email>
</author>
<published>2026-07-28T18:07:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9409e18ffe7378d202efe1cf69989df9f67b0369'/>
<id>9409e18ffe7378d202efe1cf69989df9f67b0369</id>
<content type='text'>
[ Upstream commit a3f3859cecacb64f18fd446271ece9a3b3f2d4de ]

When a caller provides a `supplied_recv` message to i_ipmi_request(),
the function increments the user's `nr_msgs` reference count. If an
error occurs later, the out_err cleanup path only frees the recv_msg
if the function allocated it itself (i.e., !supplied_recv). In the
supplied_recv case the cleanup is skipped, leaving the reference count
elevated. The caller ipmi_request_supply_msgs() does not release the
supplied_recv on error, so the reference is permanently leaked.

Fix this by explicitly reverting the reference count operations when a
supplied recv_msg with a valid user pointer is present in the error
path: decrement nr_msgs and drop the user's kref.

Cc: stable@vger.kernel.org
Fixes: b52da4054ee0 ("ipmi: Rework user message limit handling")
Signed-off-by: Wentao Liang &lt;vulab@iscas.ac.cn&gt;
Message-ID: &lt;20260603120634.3758747-1-vulab@iscas.ac.cn&gt;
Signed-off-by: Corey Minyard &lt;corey@minyard.net&gt;
[ changed `free_ipmi_user` to `free_user` in the two added `kref_put()` calls ]
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit a3f3859cecacb64f18fd446271ece9a3b3f2d4de ]

When a caller provides a `supplied_recv` message to i_ipmi_request(),
the function increments the user's `nr_msgs` reference count. If an
error occurs later, the out_err cleanup path only frees the recv_msg
if the function allocated it itself (i.e., !supplied_recv). In the
supplied_recv case the cleanup is skipped, leaving the reference count
elevated. The caller ipmi_request_supply_msgs() does not release the
supplied_recv on error, so the reference is permanently leaked.

Fix this by explicitly reverting the reference count operations when a
supplied recv_msg with a valid user pointer is present in the error
path: decrement nr_msgs and drop the user's kref.

Cc: stable@vger.kernel.org
Fixes: b52da4054ee0 ("ipmi: Rework user message limit handling")
Signed-off-by: Wentao Liang &lt;vulab@iscas.ac.cn&gt;
Message-ID: &lt;20260603120634.3758747-1-vulab@iscas.ac.cn&gt;
Signed-off-by: Corey Minyard &lt;corey@minyard.net&gt;
[ changed `free_ipmi_user` to `free_user` in the two added `kref_put()` calls ]
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tpm: Make the TPM character devices non-seekable</title>
<updated>2026-07-24T14:03:38+00:00</updated>
<author>
<name>Jaewon Yang</name>
<email>yong010301@gmail.com</email>
</author>
<published>2026-07-12T17:11:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9c513dabd4540f811585a2087f23069767a284da'/>
<id>9c513dabd4540f811585a2087f23069767a284da</id>
<content type='text'>
commit f20d61c22bcaf172d6790b6500e3838e532e71c8 upstream.

The TPM character devices expose a sequential command/response
interface, but their open handlers leave FMODE_PREAD and FMODE_PWRITE
enabled.

After a command leaves a response pending, pread(fd, buf, 16, 0x1400)
passes 0x1400 as *off to tpm_common_read(). The transfer length is
bounded by response_length, but the offset is used unchecked when
forming data_buffer + *off. A sufficiently large offset therefore causes
an out-of-bounds heap read through copy_to_user() and, if the copy
succeeds, an out-of-bounds zero-write through the following memset().

Positional I/O does not provide coherent semantics for this interface.
An arbitrary pread offset cannot represent how much of a response has
been consumed sequentially. The write callback always stores a command
at the start of data_buffer, while pwrite() does not update file-&gt;f_pos
and can leave the sequential read cursor stale.

Call nonseekable_open() from both open handlers. This removes
FMODE_PREAD and FMODE_PWRITE, causing positional reads and writes to
fail with -ESPIPE before reaching the TPM callbacks, and explicitly
marks the files non-seekable. Normal read() and write() continue to use
the existing sequential f_pos cursor, leaving the response state machine
unchanged.

Tested on Linux 6.12 with KASAN and a swtpm TPM2 device:

 - sequential partial reads returned the complete response
 - pread() and preadv() with offset 0x1400 returned -ESPIPE
 - pwrite() and pwritev() with offset zero returned -ESPIPE
 - the pending response remained intact after the rejected operations
 - a subsequent normal command/response cycle completed normally
 - no KASAN report was produced.

Fixes: 9488585b21be ("tpm: add support for partial reads")
Link: https://lore.kernel.org/all/20260710090217.191289-1-yong010301@gmail.com/
Cc: stable@vger.kernel.org
Signed-off-by: Jaewon Yang &lt;yong010301@gmail.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit f20d61c22bcaf172d6790b6500e3838e532e71c8 upstream.

The TPM character devices expose a sequential command/response
interface, but their open handlers leave FMODE_PREAD and FMODE_PWRITE
enabled.

After a command leaves a response pending, pread(fd, buf, 16, 0x1400)
passes 0x1400 as *off to tpm_common_read(). The transfer length is
bounded by response_length, but the offset is used unchecked when
forming data_buffer + *off. A sufficiently large offset therefore causes
an out-of-bounds heap read through copy_to_user() and, if the copy
succeeds, an out-of-bounds zero-write through the following memset().

Positional I/O does not provide coherent semantics for this interface.
An arbitrary pread offset cannot represent how much of a response has
been consumed sequentially. The write callback always stores a command
at the start of data_buffer, while pwrite() does not update file-&gt;f_pos
and can leave the sequential read cursor stale.

Call nonseekable_open() from both open handlers. This removes
FMODE_PREAD and FMODE_PWRITE, causing positional reads and writes to
fail with -ESPIPE before reaching the TPM callbacks, and explicitly
marks the files non-seekable. Normal read() and write() continue to use
the existing sequential f_pos cursor, leaving the response state machine
unchanged.

Tested on Linux 6.12 with KASAN and a swtpm TPM2 device:

 - sequential partial reads returned the complete response
 - pread() and preadv() with offset 0x1400 returned -ESPIPE
 - pwrite() and pwritev() with offset zero returned -ESPIPE
 - the pending response remained intact after the rejected operations
 - a subsequent normal command/response cycle completed normally
 - no KASAN report was produced.

Fixes: 9488585b21be ("tpm: add support for partial reads")
Link: https://lore.kernel.org/all/20260710090217.191289-1-yong010301@gmail.com/
Cc: stable@vger.kernel.org
Signed-off-by: Jaewon Yang &lt;yong010301@gmail.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tpm: fix event_size output in tpm1_binary_bios_measurements_show</title>
<updated>2026-07-24T14:03:38+00:00</updated>
<author>
<name>Thorsten Blum</name>
<email>thorsten.blum@linux.dev</email>
</author>
<published>2026-06-15T12:02:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0084fd985fe28f64ea12cec4bd442d66282ddb4e'/>
<id>0084fd985fe28f64ea12cec4bd442d66282ddb4e</id>
<content type='text'>
commit 1a58f6115bfb34eabcc7de8a3a9745b219179781 upstream.

Commit 186d124f07da ("tpm_eventlog.c: fix binary_bios_measurements")
split the output to write the endian-converted event header first and
then the variable-length event data.

However, the split was at sizeof(struct tcpa_event) - 1, even though
event_data was a zero-length array, and later a flexible array member,
both of which already excluded the event data.

Therefore, the current code writes the first three bytes of event_size
from the endian-converted header and then the last byte from the raw
header, which can emit a corrupted event_size on PPC64, where
do_endian_conversion() maps to be32_to_cpu().

Split one byte later to write the full endian-converted header first,
followed by the variable-length event-&gt;event_data.

Fixes: 186d124f07da ("tpm_eventlog.c: fix binary_bios_measurements")
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Thorsten Blum &lt;thorsten.blum@linux.dev&gt;
Signed-off-by: Jarkko Sakkinen &lt;jarkko@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 1a58f6115bfb34eabcc7de8a3a9745b219179781 upstream.

Commit 186d124f07da ("tpm_eventlog.c: fix binary_bios_measurements")
split the output to write the endian-converted event header first and
then the variable-length event data.

However, the split was at sizeof(struct tcpa_event) - 1, even though
event_data was a zero-length array, and later a flexible array member,
both of which already excluded the event data.

Therefore, the current code writes the first three bytes of event_size
from the endian-converted header and then the last byte from the raw
header, which can emit a corrupted event_size on PPC64, where
do_endian_conversion() maps to be32_to_cpu().

Split one byte later to write the full endian-converted header first,
followed by the variable-length event-&gt;event_data.

Fixes: 186d124f07da ("tpm_eventlog.c: fix binary_bios_measurements")
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Thorsten Blum &lt;thorsten.blum@linux.dev&gt;
Signed-off-by: Jarkko Sakkinen &lt;jarkko@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tpm: tpm_tis_spi: Use wait_woken() in wait_for_tmp_stat()</title>
<updated>2026-07-24T14:03:37+00:00</updated>
<author>
<name>Jarkko Sakkinen</name>
<email>jarkko@kernel.org</email>
</author>
<published>2026-05-09T18:51:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6b068a97958aa00a901a9b5083d74114b21f7b66'/>
<id>6b068a97958aa00a901a9b5083d74114b21f7b66</id>
<content type='text'>
commit c0c9cfb3b75def8bf200a2d4db09015806acfeaf upstream.

wait_event_interruptible_timeout() evaluates its condition after setting
the current task state to TASK_INTERRUPTIBLE.

With CONFIG_DEBUG_ATOMIC_SLEEP this triggers a warning when the IRQ wait
path is used:

    tpm_tis_status()
      tpm_tis_spi_read_bytes()
        tpm_tis_spi_transfer_full()
          spi_bus_lock()
            mutex_lock()

Address this with the following measures:

1. Call wait_tpm_stat_cond() only while tasking is running.
2. Use wait_woken() to wait for changes.

Cc: stable@vger.kernel.org # v4.19+
Cc: Linus Walleij &lt;linusw@kernel.org&gt;
Reported-by: Stefan Wahren &lt;wahrenst@gmx.net&gt;
Closes: https://lore.kernel.org/linux-integrity/6964bec7-3dbb-453b-89ef-9b990217a8b9@gmx.net/
Fixes: 1a339b658d9d ("tpm_tis_spi: Pass the SPI IRQ down to the driver")
Reviewed-by: Linus Walleij &lt;linusw@kernel.org&gt;
Tested-by: Stefan Wahren &lt;wahrenst@gmx.net&gt;
Signed-off-by: Jarkko Sakkinen &lt;jarkko@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c0c9cfb3b75def8bf200a2d4db09015806acfeaf upstream.

wait_event_interruptible_timeout() evaluates its condition after setting
the current task state to TASK_INTERRUPTIBLE.

With CONFIG_DEBUG_ATOMIC_SLEEP this triggers a warning when the IRQ wait
path is used:

    tpm_tis_status()
      tpm_tis_spi_read_bytes()
        tpm_tis_spi_transfer_full()
          spi_bus_lock()
            mutex_lock()

Address this with the following measures:

1. Call wait_tpm_stat_cond() only while tasking is running.
2. Use wait_woken() to wait for changes.

Cc: stable@vger.kernel.org # v4.19+
Cc: Linus Walleij &lt;linusw@kernel.org&gt;
Reported-by: Stefan Wahren &lt;wahrenst@gmx.net&gt;
Closes: https://lore.kernel.org/linux-integrity/6964bec7-3dbb-453b-89ef-9b990217a8b9@gmx.net/
Fixes: 1a339b658d9d ("tpm_tis_spi: Pass the SPI IRQ down to the driver")
Reviewed-by: Linus Walleij &lt;linusw@kernel.org&gt;
Tested-by: Stefan Wahren &lt;wahrenst@gmx.net&gt;
Signed-off-by: Jarkko Sakkinen &lt;jarkko@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>char: tlclk: fix use-after-free in tlclk_cleanup()</title>
<updated>2026-07-24T14:03:15+00:00</updated>
<author>
<name>James Kim</name>
<email>james010kim@gmail.com</email>
</author>
<published>2026-05-03T10:11:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=764723bd67a6c8f53a8d8309211fb039e2ebcf49'/>
<id>764723bd67a6c8f53a8d8309211fb039e2ebcf49</id>
<content type='text'>
[ Upstream commit bbf003b7794d6ad6f939fdd29f1f1bde8ac554c1 ]

This patch improves the module cleanup process in the tlclk driver to
prevent potential use-after-free and race conditions.

Currently, the file_operations structure does not specify the .owner
field, which could allow the module to be unloaded while user-space
processes are still interacting with the device. Additionally, the
tlclk_cleanup() function frees the alarm_events memory before ensuring
that blocked processes in the waitqueue are fully awakened and that the
switchover_timer has completed.

To address these cases, this patch:
- Sets '.owner = THIS_MODULE' in tlclk_fops to safely defer module
  unloading while the device is in use.
- Updates tlclk_cleanup() to explicitly wake up all blocked readers
  (wake_up_all), properly release hardware I/O regions, and safely
  delete the timer (timer_delete_sync) prior to freeing memory.

Fixes: 1a80ba882730 ("[PATCH] Telecom Clock Driver for MPCBL0010 ATCA computer blade")
Signed-off-by: James Kim &lt;james010kim@gmail.com&gt;
Link: https://patch.msgid.link/20260503101131.64219-1-james010kim@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit bbf003b7794d6ad6f939fdd29f1f1bde8ac554c1 ]

This patch improves the module cleanup process in the tlclk driver to
prevent potential use-after-free and race conditions.

Currently, the file_operations structure does not specify the .owner
field, which could allow the module to be unloaded while user-space
processes are still interacting with the device. Additionally, the
tlclk_cleanup() function frees the alarm_events memory before ensuring
that blocked processes in the waitqueue are fully awakened and that the
switchover_timer has completed.

To address these cases, this patch:
- Sets '.owner = THIS_MODULE' in tlclk_fops to safely defer module
  unloading while the device is in use.
- Updates tlclk_cleanup() to explicitly wake up all blocked readers
  (wake_up_all), properly release hardware I/O regions, and safely
  delete the timer (timer_delete_sync) prior to freeing memory.

Fixes: 1a80ba882730 ("[PATCH] Telecom Clock Driver for MPCBL0010 ATCA computer blade")
Signed-off-by: James Kim &lt;james010kim@gmail.com&gt;
Link: https://patch.msgid.link/20260503101131.64219-1-james010kim@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>hwrng: jh7110 - fix refcount leak in starfive_trng_read()</title>
<updated>2026-07-24T14:02:52+00:00</updated>
<author>
<name>Wentao Liang</name>
<email>vulab@iscas.ac.cn</email>
</author>
<published>2026-06-03T11:03:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=93dfe94d55676137d5a67d2f58a6c2a239f5c22a'/>
<id>93dfe94d55676137d5a67d2f58a6c2a239f5c22a</id>
<content type='text'>
commit 8d13f7a8450206e3f820cdb26e33e91d181071b4 upstream.

The starfive_trng_read() function acquires a runtime PM reference
via pm_runtime_get_sync() but fails to release it on two error
paths.  If starfive_trng_wait_idle() or starfive_trng_cmd() returns
an error, the function exits without calling
pm_runtime_put_sync_autosuspend(), leaving the runtime PM usage
counter permanently elevated and preventing the device from entering
runtime suspend.

Refactor the function to use a unified error path that calls
pm_runtime_put_sync_autosuspend() before returning.

Cc: stable@vger.kernel.org
Fixes: c388f458bc34 ("hwrng: starfive - Add TRNG driver for StarFive SoC")
Signed-off-by: Wentao Liang &lt;vulab@iscas.ac.cn&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 8d13f7a8450206e3f820cdb26e33e91d181071b4 upstream.

The starfive_trng_read() function acquires a runtime PM reference
via pm_runtime_get_sync() but fails to release it on two error
paths.  If starfive_trng_wait_idle() or starfive_trng_cmd() returns
an error, the function exits without calling
pm_runtime_put_sync_autosuspend(), leaving the runtime PM usage
counter permanently elevated and preventing the device from entering
runtime suspend.

Refactor the function to use a unified error path that calls
pm_runtime_put_sync_autosuspend() before returning.

Cc: stable@vger.kernel.org
Fixes: c388f458bc34 ("hwrng: starfive - Add TRNG driver for StarFive SoC")
Signed-off-by: Wentao Liang &lt;vulab@iscas.ac.cn&gt;
Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>hwrng: virtio: clamp device-reported used.len at copy_data()</title>
<updated>2026-07-24T14:02:43+00:00</updated>
<author>
<name>Michael Bommarito</name>
<email>michael.bommarito@gmail.com</email>
</author>
<published>2026-05-31T14:22:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fde19b0d4eeabae042519313c843fe6f27d41e9d'/>
<id>fde19b0d4eeabae042519313c843fe6f27d41e9d</id>
<content type='text'>
commit e3046eeada299f917a8ad883af4434bfb86556b1 upstream.

random_recv_done() stores the device-reported used.len directly into
vi-&gt;data_avail.  copy_data() then indexes vi-&gt;data[] using
vi-&gt;data_idx (advanced by previous copy_data() calls) and issues a
memcpy() without re-validating either value against the posted
buffer size sizeof(vi-&gt;data) (SMP_CACHE_BYTES bytes, typically 32
or 64).

A malicious or buggy virtio-rng backend can set used.len beyond
sizeof(vi-&gt;data), steering the memcpy() past the end of the inline
array into adjacent kmalloc-1k slab bytes.  hwrng_fillfn() mixes
those bytes into the guest RNG, and guest root can also observe
them directly via /dev/hwrng.

Concrete impact is inside the guest:

 - Memory-safety / hardening: any virtio-rng backend that
   over-reports used.len causes the driver to read past vi-&gt;data
   into unrelated slab contents.  hwrng_fillfn() is a kernel thread
   that runs as soon as the device is probed; no guest userspace
   interaction is required to first-trigger the OOB.

 - Cross-boundary leak (confidential-compute threat model): a
   malicious hypervisor cooperating with a malicious or compromised
   guest root userspace can use /dev/hwrng as a leak channel for
   guest-kernel heap data.  The host sets a large used.len, guest
   root reads /dev/hwrng, and the returned bytes contain guest
   kernel slab contents that were adjacent to vi-&gt;data.  In
   practice, confidential-compute guests (SEV-SNP, TDX) usually
   disable virtio-rng entirely, so this path is narrow, but the
   fix is still worth carrying because the underlying
   memory-safety bug contaminates the guest RNG on any host.

KASAN confirms the OOB on a 7.1-rc4 guest whose virtio-rng backend
has been patched to report used.len = 0x10000:

  BUG: KASAN: slab-out-of-bounds in virtio_read+0x394/0x5d0
  Read of size 64 at addr ffff88800ae0ba20 by task hwrng/52
  Call Trace:
   __asan_memcpy+0x23/0x60
   virtio_read+0x394/0x5d0
   hwrng_fillfn+0xb2/0x470
   kthread+0x2cc/0x3a0
  Allocated by task 1:
   probe_common+0xa5/0x660
   virtio_dev_probe+0x549/0xbc0
  The buggy address belongs to the object at ffff88800ae0b800
   which belongs to the cache kmalloc-1k of size 1024
  The buggy address is located 0 bytes to the right of
   allocated 544-byte region [ffff88800ae0b800, ffff88800ae0ba20)

Same class of bug as commit c04db81cd028 ("net/9p: Fix buffer
overflow in USB transport layer"), which hardened
usb9pfs_rx_complete() against unchecked device-reported length in
the USB 9p transport.

With the clamp at point of use and array_index_nospec() in place,
the same harness boots cleanly: copy_data() returns zero for the
bogus report, the device-supplied bytes after data_idx are
discarded, and the driver issues a fresh request.

Fixes: f7f510ec1957 ("virtio: An entropy device, as suggested by hpa.")
Cc: stable@vger.kernel.org
Suggested-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Signed-off-by: Michael Bommarito &lt;michael.bommarito@gmail.com&gt;
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Message-ID: &lt;20260531142251.2792061-1-michael.bommarito@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
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commit e3046eeada299f917a8ad883af4434bfb86556b1 upstream.

random_recv_done() stores the device-reported used.len directly into
vi-&gt;data_avail.  copy_data() then indexes vi-&gt;data[] using
vi-&gt;data_idx (advanced by previous copy_data() calls) and issues a
memcpy() without re-validating either value against the posted
buffer size sizeof(vi-&gt;data) (SMP_CACHE_BYTES bytes, typically 32
or 64).

A malicious or buggy virtio-rng backend can set used.len beyond
sizeof(vi-&gt;data), steering the memcpy() past the end of the inline
array into adjacent kmalloc-1k slab bytes.  hwrng_fillfn() mixes
those bytes into the guest RNG, and guest root can also observe
them directly via /dev/hwrng.

Concrete impact is inside the guest:

 - Memory-safety / hardening: any virtio-rng backend that
   over-reports used.len causes the driver to read past vi-&gt;data
   into unrelated slab contents.  hwrng_fillfn() is a kernel thread
   that runs as soon as the device is probed; no guest userspace
   interaction is required to first-trigger the OOB.

 - Cross-boundary leak (confidential-compute threat model): a
   malicious hypervisor cooperating with a malicious or compromised
   guest root userspace can use /dev/hwrng as a leak channel for
   guest-kernel heap data.  The host sets a large used.len, guest
   root reads /dev/hwrng, and the returned bytes contain guest
   kernel slab contents that were adjacent to vi-&gt;data.  In
   practice, confidential-compute guests (SEV-SNP, TDX) usually
   disable virtio-rng entirely, so this path is narrow, but the
   fix is still worth carrying because the underlying
   memory-safety bug contaminates the guest RNG on any host.

KASAN confirms the OOB on a 7.1-rc4 guest whose virtio-rng backend
has been patched to report used.len = 0x10000:

  BUG: KASAN: slab-out-of-bounds in virtio_read+0x394/0x5d0
  Read of size 64 at addr ffff88800ae0ba20 by task hwrng/52
  Call Trace:
   __asan_memcpy+0x23/0x60
   virtio_read+0x394/0x5d0
   hwrng_fillfn+0xb2/0x470
   kthread+0x2cc/0x3a0
  Allocated by task 1:
   probe_common+0xa5/0x660
   virtio_dev_probe+0x549/0xbc0
  The buggy address belongs to the object at ffff88800ae0b800
   which belongs to the cache kmalloc-1k of size 1024
  The buggy address is located 0 bytes to the right of
   allocated 544-byte region [ffff88800ae0b800, ffff88800ae0ba20)

Same class of bug as commit c04db81cd028 ("net/9p: Fix buffer
overflow in USB transport layer"), which hardened
usb9pfs_rx_complete() against unchecked device-reported length in
the USB 9p transport.

With the clamp at point of use and array_index_nospec() in place,
the same harness boots cleanly: copy_data() returns zero for the
bogus report, the device-supplied bytes after data_idx are
discarded, and the driver issues a fresh request.

Fixes: f7f510ec1957 ("virtio: An entropy device, as suggested by hpa.")
Cc: stable@vger.kernel.org
Suggested-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Signed-off-by: Michael Bommarito &lt;michael.bommarito@gmail.com&gt;
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Message-ID: &lt;20260531142251.2792061-1-michael.bommarito@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
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</entry>
<entry>
<title>agp/amd64: Fix broken error propagation in agp_amd64_probe()</title>
<updated>2026-07-04T11:42:19+00:00</updated>
<author>
<name>Mingyu Wang</name>
<email>25181214217@stu.xidian.edu.cn</email>
</author>
<published>2026-05-04T07:48:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=eb045714bc6a2bbb0befb7a31b996a196e188869'/>
<id>eb045714bc6a2bbb0befb7a31b996a196e188869</id>
<content type='text'>
commit b08472db93b1ccff84a7adec5779d47f0e9d3a30 upstream.

A NULL pointer dereference was observed in the AMD64 AGP driver when
running in a virtualized environment (e.g. qemu/kvm) without a physical
AMD northbridge. The crash occurs in amd64_fetch_size() when attempting
to dereference the pointer returned by node_to_amd_nb(0).

The root cause of this crash is broken error propagation in
agp_amd64_probe(): When no AMD northbridges are found, cache_nbs()
correctly returns -ENODEV. However, the probe function erroneously
checks the return value against exactly -1, rather than &lt; 0.

As a result, the hardware absence error is masked, allowing the driver
to improperly proceed with initialization. It eventually calls
agp_add_bridge(), which invokes amd64_fetch_size(). Since the hardware
does not exist, node_to_amd_nb(0) returns NULL, leading to a General
Protection Fault (GPF) when accessing its -&gt;misc member.

Fix the issue by correcting the error check in agp_amd64_probe() to
abort properly when cache_nbs() returns any negative error code. This
prevents the driver from erroneously proceeding without hardware, thereby
avoiding the subsequent NULL pointer dereference at its source.

Fixes: a32073bffc65 ("[PATCH] x86_64: Clean and enhance up K8 northbridge access code")
Signed-off-by: Mingyu Wang &lt;25181214217@stu.xidian.edu.cn&gt;
Signed-off-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Reviewed-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Cc: stable@vger.kernel.org # v2.6.18+
Link: https://patch.msgid.link/20260504074823.99377-1-w15303746062@163.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
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<pre>
commit b08472db93b1ccff84a7adec5779d47f0e9d3a30 upstream.

A NULL pointer dereference was observed in the AMD64 AGP driver when
running in a virtualized environment (e.g. qemu/kvm) without a physical
AMD northbridge. The crash occurs in amd64_fetch_size() when attempting
to dereference the pointer returned by node_to_amd_nb(0).

The root cause of this crash is broken error propagation in
agp_amd64_probe(): When no AMD northbridges are found, cache_nbs()
correctly returns -ENODEV. However, the probe function erroneously
checks the return value against exactly -1, rather than &lt; 0.

As a result, the hardware absence error is masked, allowing the driver
to improperly proceed with initialization. It eventually calls
agp_add_bridge(), which invokes amd64_fetch_size(). Since the hardware
does not exist, node_to_amd_nb(0) returns NULL, leading to a General
Protection Fault (GPF) when accessing its -&gt;misc member.

Fix the issue by correcting the error check in agp_amd64_probe() to
abort properly when cache_nbs() returns any negative error code. This
prevents the driver from erroneously proceeding without hardware, thereby
avoiding the subsequent NULL pointer dereference at its source.

Fixes: a32073bffc65 ("[PATCH] x86_64: Clean and enhance up K8 northbridge access code")
Signed-off-by: Mingyu Wang &lt;25181214217@stu.xidian.edu.cn&gt;
Signed-off-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Reviewed-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Cc: stable@vger.kernel.org # v2.6.18+
Link: https://patch.msgid.link/20260504074823.99377-1-w15303746062@163.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipmi:ssif: NULL thread on error</title>
<updated>2026-06-19T11:39:38+00:00</updated>
<author>
<name>Corey Minyard</name>
<email>corey@minyard.net</email>
</author>
<published>2026-04-21T11:50:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=666bd0598f371738c0c15cd1e37c8d14806c2b2c'/>
<id>666bd0598f371738c0c15cd1e37c8d14806c2b2c</id>
<content type='text'>
commit a8aebe93a4938c0ca1941eeaae821738f869be3d upstream.

Cleanup code was checking the thread for NULL, but it was possibly
a PTR_ERR() in one spot.

Spotted with static analysis.

Link: https://sourceforge.net/p/openipmi/mailman/message/59324676/
Fixes: 75c486cb1bca ("ipmi:ssif: Clean up kthread on errors")
Cc: &lt;stable@vger.kernel.org&gt; # 91eb7ec72612: ipmi:ssif: Remove unnecessary indention
Cc: stable@vger.kernel.org
Signed-off-by: Corey Minyard &lt;corey@minyard.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
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<pre>
commit a8aebe93a4938c0ca1941eeaae821738f869be3d upstream.

Cleanup code was checking the thread for NULL, but it was possibly
a PTR_ERR() in one spot.

Spotted with static analysis.

Link: https://sourceforge.net/p/openipmi/mailman/message/59324676/
Fixes: 75c486cb1bca ("ipmi:ssif: Clean up kthread on errors")
Cc: &lt;stable@vger.kernel.org&gt; # 91eb7ec72612: ipmi:ssif: Remove unnecessary indention
Cc: stable@vger.kernel.org
Signed-off-by: Corey Minyard &lt;corey@minyard.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipmi:ssif: Remove unnecessary indention</title>
<updated>2026-06-19T11:39:37+00:00</updated>
<author>
<name>Corey Minyard</name>
<email>corey@minyard.net</email>
</author>
<published>2026-04-13T12:09:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=318a0403b270fb045b23235aba686d997d8aca05'/>
<id>318a0403b270fb045b23235aba686d997d8aca05</id>
<content type='text'>
commit 91eb7ec7261254b6875909df767185838598e21e upstream.

A section was in {} that didn't need to be, move the variable
definition to the top and set th eindentino properly.

Signed-off-by: Corey Minyard &lt;corey@minyard.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
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<pre>
commit 91eb7ec7261254b6875909df767185838598e21e upstream.

A section was in {} that didn't need to be, move the variable
definition to the top and set th eindentino properly.

Signed-off-by: Corey Minyard &lt;corey@minyard.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
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</content>
</entry>
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