linux-stable.git/drivers/block, branch v7.2.4 Linux kernel stable tree zloop: truncate finished zones to zone capacity 2026-09-07T15:37:27+00:00 Xu Rao raoxu@uniontech.com 2026-08-04T02:34:03+00:00 23cb8d5fb33dce9593dab5cea4ea3cf21ef19607 commit 72e67c118642634c25465db0c8bcfa54c4ce086c upstream. The size of a sequential zone backing file records the amount of data written and is used to restore the zone state. A backing file whose size is equal to the zone capacity is restored as a full zone, while a file larger than the zone capacity is rejected as invalid. However, zloop_finish_zone() currently truncates the backing file to the zone size. For devices with a reduced zone capacity, finishing a zone therefore creates a backing file larger than the zone capacity. After the device is removed and later re-added, that zone file is rejected instead of being restored as a full zone. Truncate finished sequential zones to the zone capacity, matching the persistent representation accepted by zloop_update_seq_zone() for a full zone. Suggested-by: Damien Le Moal <dlemoal@kernel.org> Fixes: eb0570c7df23 ("block: new zoned loop block device driver") Cc: stable@vger.kernel.org Signed-off-by: Xu Rao <raoxu@uniontech.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://patch.msgid.link/B39E5FD81D1A07F4+20260804023403.939767-1-raoxu@uniontech.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 72e67c118642634c25465db0c8bcfa54c4ce086c upstream.

The size of a sequential zone backing file records the amount of data
written and is used to restore the zone state. A backing file whose size
is equal to the zone capacity is restored as a full zone, while a file
larger than the zone capacity is rejected as invalid.

However, zloop_finish_zone() currently truncates the backing file to the
zone size. For devices with a reduced zone capacity, finishing a zone
therefore creates a backing file larger than the zone capacity. After the
device is removed and later re-added, that zone file is rejected instead
of being restored as a full zone.

Truncate finished sequential zones to the zone capacity, matching the
persistent representation accepted by zloop_update_seq_zone() for a full
zone.

Suggested-by: Damien Le Moal <dlemoal@kernel.org>
Fixes: eb0570c7df23 ("block: new zoned loop block device driver")
Cc: stable@vger.kernel.org
Signed-off-by: Xu Rao <raoxu@uniontech.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://patch.msgid.link/B39E5FD81D1A07F4+20260804023403.939767-1-raoxu@uniontech.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
zram: validate deflate params 2026-09-07T15:36:40+00:00 Sergey Senozhatsky senozhatsky@chromium.org 2026-07-29T04:57:36+00:00 e23fac4ab2a5728386477b98a402a1042b21bffb commit ec7607ac4717ff521c9c1e9d8271c26293345513 upstream. We must validate user-supplied deflate winbits before we pass it to zlib_deflate_workspacesize(), which triggers BUG_ON() if winbits value is outside of valid ranges. Link: https://lore.kernel.org/20260729045745.775973-3-senozhatsky@chromium.org Fixes: dc75a0d93bd5 ("zram: support deflate-specific params") Link: https://sashiko.dev/#/patchset/20260728092935.31139-1-haoqinhuang7@gmail.com Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Haoqin Huang <haoqinhuang7@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit ec7607ac4717ff521c9c1e9d8271c26293345513 upstream.

We must validate user-supplied deflate winbits before we pass it to
zlib_deflate_workspacesize(), which triggers BUG_ON() if winbits value is
outside of valid ranges.

Link: https://lore.kernel.org/20260729045745.775973-3-senozhatsky@chromium.org
Fixes: dc75a0d93bd5 ("zram: support deflate-specific params")
Link: https://sashiko.dev/#/patchset/20260728092935.31139-1-haoqinhuang7@gmail.com
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Haoqin Huang <haoqinhuang7@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
zram: set default primary compressor in zram_destroy_comps() 2026-09-07T15:36:40+00:00 Sergey Senozhatsky senozhatsky@chromium.org 2026-07-29T04:57:35+00:00 dea8f13c3dfad8b990f8ea96c997aabeebbc1d22 commit dde75313eed0b014c437f48dd75c0308b592cbf9 upstream. Patch series "zram: fix zram issues reported by sashiko". Sashiko drove by and reported [1] a couple of zram issues: a possible BUG_ON() in zlib code due to missing winbits range validation and one possible NULL-ptr dereference in zcomp. Both are low risk yet still worth fixing. This patch (of 2): zram_destroy_comps() resets all compressors and leaves them set to NULL, including the primary one, which is invalid device state, as now comp_algorithm_show()->strcmp() can be called on a NULL compressor. Set default primary compressor in zram_destroy_comps(). Link: https://lore.kernel.org/20260729045745.775973-2-senozhatsky@chromium.org Fixes: 486fd58af7ac ("zram: don't free statically defined names") Link: https://sashiko.dev/#/patchset/20260728092935.31139-1-haoqinhuang7@gmail.com [1] Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Haoqin Huang <haoqinhuang7@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit dde75313eed0b014c437f48dd75c0308b592cbf9 upstream.

Patch series "zram: fix zram issues reported by sashiko".

Sashiko drove by and reported [1] a couple of zram issues:
a possible BUG_ON() in zlib code due to missing winbits range
validation and one possible NULL-ptr dereference in zcomp.
Both are low risk yet still worth fixing.


This patch (of 2):

zram_destroy_comps() resets all compressors and leaves them set to NULL,
including the primary one, which is invalid device state, as now
comp_algorithm_show()->strcmp() can be called on a NULL compressor.  Set
default primary compressor in zram_destroy_comps().

Link: https://lore.kernel.org/20260729045745.775973-2-senozhatsky@chromium.org
Fixes: 486fd58af7ac ("zram: don't free statically defined names")
Link: https://sashiko.dev/#/patchset/20260728092935.31139-1-haoqinhuang7@gmail.com [1]
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Haoqin Huang <haoqinhuang7@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
zram: fix out-of-bounds access in writeback_store() 2026-09-07T15:36:40+00:00 Longlong Xia xialonglong@kylinos.cn 2026-08-04T06:59:18+00:00 07a82a66f8c1894d92e51d97542c32ebf2c51b09 commit 894913e2d35c46ff19a77530907771ae57862b96 upstream. Patch series "zram: fix stale scan bounds after reinitialization". Both writeback_store() and read_block_state() derive their table scan bounds from zram->disksize before acquiring dev_lock. If the device is reset and reinitialized with a smaller disksize between that read and lock acquisition, the bound can describe the old table while the scan operates on the new one. This can lead to out-of-bounds slot accesses. Move both bound calculations under dev_lock so each bound remains consistent with the table throughout its scan. Keep the fixes separate because the affected interfaces originate from different commits and can be backported independently. This patch (of 2): writeback_store() calculates the table scan bounds before taking dev_lock. A reset followed by reconfiguration with a smaller disksize can therefore replace zram->table while writeback_store() is waiting for the lock. Once it acquires the lock, it sees an initialized device but scans the new table using the old upper bound, resulting in an out-of-bounds access. Calculate the number of pages while holding dev_lock so the scan bound matches the table protected by the lock. Link: https://lore.kernel.org/20260804065919.3970386-1-xialonglong2025@163.com Link: https://lore.kernel.org/20260804065919.3970386-2-xialonglong2025@163.com Fixes: a939888ec38b ("zram: support idle/huge page writeback") Assisted-by: Codex:gpt-5.6-sol Signed-off-by: Longlong Xia <xialonglong@kylinos.cn> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Minchan Kim <minchan@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 894913e2d35c46ff19a77530907771ae57862b96 upstream.

Patch series "zram: fix stale scan bounds after reinitialization".

Both writeback_store() and read_block_state() derive their table scan
bounds from zram->disksize before acquiring dev_lock.  If the device is
reset and reinitialized with a smaller disksize between that read and lock
acquisition, the bound can describe the old table while the scan operates
on the new one.  This can lead to out-of-bounds slot accesses.

Move both bound calculations under dev_lock so each bound remains
consistent with the table throughout its scan.  Keep the fixes separate
because the affected interfaces originate from different commits and can
be backported independently.


This patch (of 2):

writeback_store() calculates the table scan bounds before taking dev_lock.
A reset followed by reconfiguration with a smaller disksize can therefore
replace zram->table while writeback_store() is waiting for the lock.  Once
it acquires the lock, it sees an initialized device but scans the new
table using the old upper bound, resulting in an out-of-bounds access.

Calculate the number of pages while holding dev_lock so the scan bound
matches the table protected by the lock.

Link: https://lore.kernel.org/20260804065919.3970386-1-xialonglong2025@163.com
Link: https://lore.kernel.org/20260804065919.3970386-2-xialonglong2025@163.com
Fixes: a939888ec38b ("zram: support idle/huge page writeback")
Assisted-by: Codex:gpt-5.6-sol
Signed-off-by: Longlong Xia <xialonglong@kylinos.cn>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
zram: fix out-of-bounds access in read_block_state() 2026-09-07T15:36:40+00:00 Longlong Xia xialonglong@kylinos.cn 2026-08-04T06:59:19+00:00 5e458fa714a55b6b64a9fe0c6d4fa609609f9ec3 commit 391f057f44a51cc9418da5cba78b014324174264 upstream. read_block_state() calculates nr_pages before taking dev_lock. If the device is reset and reinitialized with a smaller disksize before lock acquisition, nr_pages still describes the old table. The subsequent loop can then call slot_lock() past the end of the newly allocated table. Read disksize after acquiring dev_lock and checking that the device is initialized. The read lock then keeps the table and its bound stable for the duration of the scan. Link: https://lore.kernel.org/20260804065919.3970386-3-xialonglong2025@163.com Fixes: c0265342bff4 ("zram: introduce zram memory tracking") Assisted-by: Codex:gpt-5.6-sol Signed-off-by: Longlong Xia <xialonglong@kylinos.cn> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Minchan Kim <minchan@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 391f057f44a51cc9418da5cba78b014324174264 upstream.

read_block_state() calculates nr_pages before taking dev_lock.  If the
device is reset and reinitialized with a smaller disksize before lock
acquisition, nr_pages still describes the old table.  The subsequent loop
can then call slot_lock() past the end of the newly allocated table.

Read disksize after acquiring dev_lock and checking that the device is
initialized.  The read lock then keeps the table and its bound stable for
the duration of the scan.

Link: https://lore.kernel.org/20260804065919.3970386-3-xialonglong2025@163.com
Fixes: c0265342bff4 ("zram: introduce zram memory tracking")
Assisted-by: Codex:gpt-5.6-sol
Signed-off-by: Longlong Xia <xialonglong@kylinos.cn>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
null_blk: fix UBSAN shift-out-of-bounds when zone_size is 0 or overflows 2026-08-27T12:35:22+00:00 Rik van Riel riel@surriel.com 2026-08-08T15:42:39+00:00 a04b3afd4f02a6d7de9015cc7332141c5046c301 commit 95491fb05105b61050cb623a5e0227eb26aa3525 upstream. null_zone_no() does sect >> ilog2(dev->zone_size_sects). When zone_size_sects is 0, ilog2(0) returns -1, producing shift exponent -1 which UBSAN reports as shift-out-of-bounds. UBSAN: shift-out-of-bounds in drivers/block/null_blk/zoned.c:21:14 shift exponent -1 is negative Call Trace: null_zone_no drivers/block/null_blk/zoned.c:21 [inline] null_process_zoned_cmd+0xf76/0xf80 drivers/block/null_blk/zoned.c:728 null_handle_cmd drivers/block/null_blk/main.c:1455 [inline] null_queue_rq+0x8bc/0xe70 drivers/block/null_blk/main.c:1703 __blk_mq_issue_directly block/blk-mq.c:2694 [inline] blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2754 blk_mq_submit_bio+0x20c0/0x2a40 block/blk-mq.c:3208 submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790 block_read_full_folio+0x7a6/0x810 fs/buffer.c:2463 filemap_read_folio+0x12c/0x3a0 mm/filemap.c:2510 read_part_sector+0xb6/0x2b0 block/partitions/core.c:724 adfspart_check_ICS+0xb1/0x960 block/partitions/acorn.c:357 check_partition block/partitions/core.c:143 [inline] blk_add_partitions block/partitions/core.c:591 [inline] bdev_disk_changed+0x851/0x17a0 block/partitions/core.c:695 blkdev_get_whole+0x372/0x510 block/bdev.c:751 add_disk_final block/genhd.c:412 [inline] add_disk_fwnode+0x24b/0x3a0 block/genhd.c:606 null_add_dev+0x130b/0x1d70 drivers/block/null_blk/main.c:2052 nullb_device_power_store+0x240/0x380 drivers/block/null_blk/main.c:501 configfs_write_iter+0x337/0x430 fs/configfs/file.c:229 Syzkaller triggers this by creating a zoned null_blk device via configfs. The Call Trace shows configfs_write_iter in configfs/file.c handling a write to power file, which calls nullb_device_power_store in main.c, which calls null_add_dev in main.c, which calls add_disk in genhd.c, which triggers partition scan via bdev_disk_changed in partitions/core.c. A zoned null_blk device with zone_size 0 should not be legal. Existing code tries to reject it via is_power_of_2() check in zoned.c and !zone_size check in main.c, but syzkaller can still reach null_zone_no() with zone_size_sects 0 via two paths: 1. Direct 0 via configfs: zone_size attribute store in main.c has NULLB_DEVICE_ATTR(zone_size, ulong, NULL) with no validation callback, so echo 0 > zone_size succeeds before power store. If zoned is false at power store time, the !zone_size check in main.c is skipped, and later zoned set true leaves zone_size 0. 2. Large value overflow: mb_to_sects() in zoned.c does (sector_t)mb * SZ_1M >> SECTOR_SHIFT which is mb * 2048. If mb is 1UL << 53 (9PB), mb * 2048 overflows 64-bit to 0. The value is power-of-two so is_power_of_2() passes, but mb_to_sects() returns 0. Check for zero zone_size explicitly in null_init_zoned_dev() in zoned.c, returning -EINVAL with "must be non-zero power-of-two". Check for zero zone_size_sects after mb_to_sects() conversion, returning -EINVAL for overflow case. Keep defensive check in null_zone_no() returning 0 for zero sectors to avoid shift out-of-bounds even if zero slips through. This change should be safe because zone_size is set once in null_init_zoned_dev() under device lock and never changes after, and 0 is never valid for a zoned device. Returning -EINVAL at init time fails device creation early with clear error, while defensive return 0 in null_zone_no() makes zoned command fail via offline zone check. No new locking is introduced. Reported-by: syzbot+abd6a8dca0f2b7726060@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=abd6a8dca0f2b7726060 Link: https://lore.kernel.org/all/6a75205c.01d0871a.3a0d52.0033.GAE@google.com/ Fixes: 8a3cf049af68 ("null_blk: add zoned block device emulation") Cc: stable@vger.kernel.org Assisted-by: Hermes:muse-spark-1.2 syzkaller Signed-off-by: Rik van Riel <riel@surriel.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://patch.msgid.link/20260808114239.69167f68@fangorn Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 95491fb05105b61050cb623a5e0227eb26aa3525 upstream.

null_zone_no() does sect >> ilog2(dev->zone_size_sects). When
zone_size_sects is 0, ilog2(0) returns -1, producing shift exponent -1
which UBSAN reports as shift-out-of-bounds.

  UBSAN: shift-out-of-bounds in drivers/block/null_blk/zoned.c:21:14
  shift exponent -1 is negative
  Call Trace:
   null_zone_no drivers/block/null_blk/zoned.c:21 [inline]
   null_process_zoned_cmd+0xf76/0xf80 drivers/block/null_blk/zoned.c:728
   null_handle_cmd drivers/block/null_blk/main.c:1455 [inline]
   null_queue_rq+0x8bc/0xe70 drivers/block/null_blk/main.c:1703
   __blk_mq_issue_directly block/blk-mq.c:2694 [inline]
   blk_mq_try_issue_directly+0x3f4/0x880 block/blk-mq.c:2754
   blk_mq_submit_bio+0x20c0/0x2a40 block/blk-mq.c:3208
   submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790
   block_read_full_folio+0x7a6/0x810 fs/buffer.c:2463
   filemap_read_folio+0x12c/0x3a0 mm/filemap.c:2510
   read_part_sector+0xb6/0x2b0 block/partitions/core.c:724
   adfspart_check_ICS+0xb1/0x960 block/partitions/acorn.c:357
   check_partition block/partitions/core.c:143 [inline]
   blk_add_partitions block/partitions/core.c:591 [inline]
   bdev_disk_changed+0x851/0x17a0 block/partitions/core.c:695
   blkdev_get_whole+0x372/0x510 block/bdev.c:751
   add_disk_final block/genhd.c:412 [inline]
   add_disk_fwnode+0x24b/0x3a0 block/genhd.c:606
   null_add_dev+0x130b/0x1d70 drivers/block/null_blk/main.c:2052
   nullb_device_power_store+0x240/0x380 drivers/block/null_blk/main.c:501
   configfs_write_iter+0x337/0x430 fs/configfs/file.c:229

Syzkaller triggers this by creating a zoned null_blk device via
configfs. The Call Trace shows configfs_write_iter in configfs/file.c
handling a write to power file, which calls nullb_device_power_store in
main.c, which calls null_add_dev in main.c, which calls add_disk in
genhd.c, which triggers partition scan via bdev_disk_changed in
partitions/core.c.

A zoned null_blk device with zone_size 0 should not be legal. Existing
code tries to reject it via is_power_of_2() check in zoned.c and
!zone_size check in main.c, but syzkaller can still reach
null_zone_no() with zone_size_sects 0 via two paths:

1. Direct 0 via configfs: zone_size attribute store in main.c has
NULLB_DEVICE_ATTR(zone_size, ulong, NULL) with no validation callback,
so echo 0 > zone_size succeeds before power store. If zoned is false
at power store time, the !zone_size check in main.c is skipped, and
later zoned set true leaves zone_size 0.

2. Large value overflow: mb_to_sects() in zoned.c does
(sector_t)mb * SZ_1M >> SECTOR_SHIFT which is mb * 2048. If mb is
1UL << 53 (9PB), mb * 2048 overflows 64-bit to 0. The value is
power-of-two so is_power_of_2() passes, but mb_to_sects() returns 0.

Check for zero zone_size explicitly in null_init_zoned_dev() in
zoned.c, returning -EINVAL with "must be non-zero power-of-two".
Check for zero zone_size_sects after mb_to_sects() conversion,
returning -EINVAL for overflow case. Keep defensive check in
null_zone_no() returning 0 for zero sectors to avoid shift out-of-bounds
even if  zero slips through.

This change should be safe because zone_size is set once in
null_init_zoned_dev() under device lock and never changes after, and 0
is never valid for a zoned device. Returning -EINVAL at init time fails
device creation early with clear error, while defensive return 0 in
null_zone_no() makes zoned command fail via offline zone check.
No new locking is introduced.

Reported-by: syzbot+abd6a8dca0f2b7726060@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=abd6a8dca0f2b7726060
Link: https://lore.kernel.org/all/6a75205c.01d0871a.3a0d52.0033.GAE@google.com/
Fixes: 8a3cf049af68 ("null_blk: add zoned block device emulation")
Cc: stable@vger.kernel.org
Assisted-by: Hermes:muse-spark-1.2 syzkaller
Signed-off-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://patch.msgid.link/20260808114239.69167f68@fangorn
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge tag 'block-7.2-20260815' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux 2026-08-16T14:00:40+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-08-16T14:00:40+00:00 dcb68831eac76dbfda1cf5930d3003d938890d34 Pull block fix from Jens Axboe: "A single fix for a regression in this cycle, where drbd would leak shared secrets over netlink. This restores the behavior to match what we had before" * tag 'block-7.2-20260815' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: drbd: don't leak the shared secret to unprivileged netlink dumps 
Pull block fix from Jens Axboe:
 "A single fix for a regression in this cycle, where drbd would leak
  shared secrets over netlink. This restores the behavior to match
  what we had before"

* tag 'block-7.2-20260815' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  drbd: don't leak the shared secret to unprivileged netlink dumps
drbd: don't leak the shared secret to unprivileged netlink dumps 2026-08-16T02:00:10+00:00 Christoph Böhmwalder christoph.boehmwalder@linbit.com 2026-08-14T15:16:17+00:00 c71bf113dfdf426bdaf106636f573ef87b6613a0 The conversion to explicit netlink serialization dropped the exclude_sensitive parameter from net_conf_to_skb(), so each caller has to sanitize by hand. Two dump paths were missed: drbd_nl_get_connections_dumpit() and the volume-less connection branch of get_one_status(). Neither op carries GENL_ADMIN_PERM, so any unprivileged local user could read the CRAM-HMAC secret. Add a net_conf_to_skb_sanitized() wrapper and route all three callers through it. Fixes: 8098eeb693c4 ("drbd: replace genl_magic with explicit netlink serialization") Reported-by: Vivek Parikh <vivek.parikh@breachx.ai> Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> Link: https://patch.msgid.link/20260814151617.73752-1-christoph.boehmwalder@linbit.com Signed-off-by: Jens Axboe <axboe@kernel.dk> 
The conversion to explicit netlink serialization dropped the
exclude_sensitive parameter from net_conf_to_skb(), so each caller has
to sanitize by hand. Two dump paths were missed:
drbd_nl_get_connections_dumpit() and the volume-less connection branch
of get_one_status(). Neither op carries GENL_ADMIN_PERM, so any
unprivileged local user could read the CRAM-HMAC secret.

Add a net_conf_to_skb_sanitized() wrapper and route all three callers
through it.

Fixes: 8098eeb693c4 ("drbd: replace genl_magic with explicit netlink serialization")
Reported-by: Vivek Parikh <vivek.parikh@breachx.ai>
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Link: https://patch.msgid.link/20260814151617.73752-1-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merge tag 'block-7.2-20260731' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux 2026-07-31T23:42:34+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-07-31T23:42:34+00:00 f01618fd7915bd2acf945e47bf987383a60c4c45 Pull block fixes from Jens Axboe: - A set of fixes for s390/dasd, via Stefan - Fix for a missing stop of the timeout timer, if a disk has never been added - Clear kernel owned fields on ublk setup by default * tag 'block-7.2-20260731' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: s390/dasd: Fix undersized format-check buffer s390/dasd: Fix potential NULL pointer dereference s390/dasd: Fix path verification interrupted by concurrent dasd_sleep_on_immediatly block: stop the timeout timer when releasing a never added disk ublk: reset kernel-owned dev_info fields in ublk_ctrl_add_dev() 
Pull block fixes from Jens Axboe:

 - A set of fixes for s390/dasd, via Stefan

 - Fix for a missing stop of the timeout timer, if a disk has never been
   added

 - Clear kernel owned fields on ublk setup by default

* tag 'block-7.2-20260731' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  s390/dasd: Fix undersized format-check buffer
  s390/dasd: Fix potential NULL pointer dereference
  s390/dasd: Fix path verification interrupted by concurrent dasd_sleep_on_immediatly
  block: stop the timeout timer when releasing a never added disk
  ublk: reset kernel-owned dev_info fields in ublk_ctrl_add_dev()
ublk: reset kernel-owned dev_info fields in ublk_ctrl_add_dev() 2026-07-27T17:08:48+00:00 Ming Lei tom.leiming@gmail.com 2026-07-26T14:50:25+00:00 e65848e4ce352bac9e3465099354c8b8f845391f ublk_ctrl_add_dev() memcpy()s the userspace ublksrv_ctrl_dev_info into ub->dev_info and then fixes up the fields the driver owns, but misses ->state and ->ublksrv_pid. A device added with ->state = UBLK_S_DEV_LIVE passes the "->state != UBLK_S_DEV_DEAD" test that ublk_stop_dev_unlocked() uses as its proxy for "a disk is attached", while ->ub_disk is still NULL, so DEL_DEV right after ADD_DEV oopses in del_gendisk(). UBLK_S_DEV_QUIESCED plus UBLK_F_USER_RECOVERY dies one step earlier, in ublk_force_abort_dev(). A poisoned ->state also gets START_USER_RECOVERY and the char device read/write path onto a device that was never started, and wedges START_DEV at -EEXIST. A poisoned ->ublksrv_pid just makes GET_DEV_INFO report an unrelated task as the ublk server. Reset both after the memcpy(), as ublk_detach_disk() does. Userspace only ever reads these back, so correcting them silently breaks nothing. ADD_DEV has copied ->state in unsanitized since ublk was merged, but back then it was harmless: the gendisk was allocated during ADD_DEV, and both teardown and the START_DEV -EEXIST check keyed off disk_live() rather than ->state. The oops became reachable once the disk allocation moved to START_DEV and those checks switched to ->state. Fixes: 6d9e6dfdf3b2 ("ublk: defer disk allocation") Cc: stable@vger.kernel.org Signed-off-by: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Caleb Sander Mateos <csander@purestorage.com> Link: https://patch.msgid.link/20260726145025.1507383-1-tom.leiming@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> 
ublk_ctrl_add_dev() memcpy()s the userspace ublksrv_ctrl_dev_info into
ub->dev_info and then fixes up the fields the driver owns, but misses
->state and ->ublksrv_pid.

A device added with ->state = UBLK_S_DEV_LIVE passes the
"->state != UBLK_S_DEV_DEAD" test that ublk_stop_dev_unlocked() uses as its
proxy for "a disk is attached", while ->ub_disk is still NULL, so DEL_DEV
right after ADD_DEV oopses in del_gendisk().  UBLK_S_DEV_QUIESCED plus
UBLK_F_USER_RECOVERY dies one step earlier, in ublk_force_abort_dev().  A
poisoned ->state also gets START_USER_RECOVERY and the char device
read/write path onto a device that was never started, and wedges START_DEV
at -EEXIST.  A poisoned ->ublksrv_pid just makes GET_DEV_INFO report an
unrelated task as the ublk server.

Reset both after the memcpy(), as ublk_detach_disk() does.  Userspace only
ever reads these back, so correcting them silently breaks nothing.

ADD_DEV has copied ->state in unsanitized since ublk was merged, but back
then it was harmless: the gendisk was allocated during ADD_DEV, and both
teardown and the START_DEV -EEXIST check keyed off disk_live() rather than
->state.  The oops became reachable once the disk allocation moved to
START_DEV and those checks switched to ->state.

Fixes: 6d9e6dfdf3b2 ("ublk: defer disk allocation")
Cc: stable@vger.kernel.org
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Link: https://patch.msgid.link/20260726145025.1507383-1-tom.leiming@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>