kernel/linux.git/drivers/block, branch v6.1.175

drbd: Balance RCU calls in drbd_adm_dump_devices()

2026-06-01T15:39:04+00:00

[ Upstream commit 2b31e86387e60b3689339f0f0fbb4d3623d9d494 ] Make drbd_adm_dump_devices() call rcu_read_lock() before rcu_read_unlock() is called. This has been detected by the Clang thread-safety analyzer. Tested-by: Christoph Böhmwalder Reviewed-by: Christoph Hellwig Cc: Andreas Gruenbacher Fixes: a55bbd375d18 ("drbd: Backport the "status" command") Signed-off-by: Bart Van Assche Link: https://patch.msgid.link/20260326214054.284593-1-bvanassche@acm.org Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

rbd: fix null-ptr-deref when device_add_disk() fails

2026-06-01T15:38:47+00:00

commit d1fef92e414433ca7b89abf85cb0df42b8d475eb upstream. do_rbd_add() publishes the device with device_add() before calling device_add_disk(). If device_add_disk() fails after device_add() succeeds, the error path calls rbd_free_disk() directly and then later falls through to rbd_dev_device_release(), which calls rbd_free_disk() again. This double teardown can leave blk-mq cleanup operating on invalid state and trigger a null-ptr-deref in __blk_mq_free_map_and_rqs(), reached from blk_mq_free_tag_set(). Fix this by following the normal remove ordering: call device_del() before rbd_dev_device_release() when device_add_disk() fails after device_add(). That keeps the teardown sequence consistent and avoids re-entering disk cleanup through the wrong path. The bug was first flagged by an experimental analysis tool we are developing for kernel memory-management bugs while analyzing v6.13-rc1. The tool is still under development and is not yet publicly available. We reproduced the bug on v7.0 with a real Ceph backend and a QEMU x86_64 guest booted with KASAN and CONFIG_FAILSLAB enabled. The reproducer confines failslab injections to the __add_disk() range and injects fail-nth while mapping an RBD image through /sys/bus/rbd/add_single_major. On the unpatched kernel, fail-nth=4 reliably triggered the fault: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 UID: 0 PID: 273 Comm: bash Not tainted 7.0.0-01247-gd60bc1401583 #6 PREEMPT(lazy) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 RIP: 0010:__blk_mq_free_map_and_rqs+0x8c/0x240 Code: 00 00 48 8b 6b 60 41 89 f4 49 c1 e4 03 4c 01 e5 45 85 ed 0f 85 0a 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 e9 48 c1 e9 03 <80> 3c 01 00 0f 85 31 01 00 00 4c 8b 6d 00 4d 85 ed 0f 84 e2 00 00 RSP: 0018:ff1100000ab0fac8 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ff1100000c4806a0 RCX: 0000000000000000 RDX: 0000000000000002 RSI: 0000000000000000 RDI: ff1100000c4806f4 RBP: 0000000000000000 R08: 0000000000000001 R09: ffe21c000189001b R10: ff1100000c4800df R11: ff1100006cf37be0 R12: 0000000000000000 R13: 0000000000000000 R14: ff1100000c480700 R15: ff1100000c480004 FS: 00007f0fbe8fe740(0000) GS:ff110000e5851000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe53473b2e0 CR3: 0000000012eef000 CR4: 00000000007516f0 PKRU: 55555554 Call Trace: blk_mq_free_tag_set+0x77/0x460 do_rbd_add+0x1446/0x2b80 ? __pfx_do_rbd_add+0x10/0x10 ? lock_acquire+0x18c/0x300 ? find_held_lock+0x2b/0x80 ? sysfs_file_kobj+0xb6/0x1b0 ? __pfx_sysfs_kf_write+0x10/0x10 kernfs_fop_write_iter+0x2f4/0x4a0 vfs_write+0x98e/0x1000 ? expand_files+0x51f/0x850 ? __pfx_vfs_write+0x10/0x10 ksys_write+0xf2/0x1d0 ? __pfx_ksys_write+0x10/0x10 do_syscall_64+0x115/0x690 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0fbea15907 Code: 10 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24 RSP: 002b:00007ffe22346ea8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000058 RCX: 00007f0fbea15907 RDX: 0000000000000058 RSI: 0000563ace6c0ef0 RDI: 0000000000000001 RBP: 0000563ace6c0ef0 R08: 0000563ace6c0ef0 R09: 6b6435726d694141 R10: 5250337279762f78 R11: 0000000000000246 R12: 0000000000000058 R13: 00007f0fbeb1c780 R14: ff1100000c480700 R15: ff1100000c480004 With this fix applied, rerunning the reproducer over fail-nth=1..256 yields no KASAN reports. [ idryomov: rename err_out_device_del -> err_out_device ] Cc: stable@vger.kernel.org Fixes: 27c97abc30e2 ("rbd: add add_disk() error handling") Signed-off-by: Zilin Guan Signed-off-by: Dawei Feng Reviewed-by: Ilya Dryomov Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman

ublk: fix deadlock when reading partition table

2026-06-01T15:38:41+00:00

[ Upstream commit c258f5c4502c9667bccf5d76fa731ab9c96687c1 ] When one process(such as udev) opens ublk block device (e.g., to read the partition table via bdev_open()), a deadlock[1] can occur: 1. bdev_open() grabs disk->open_mutex 2. The process issues read I/O to ublk backend to read partition table 3. In __ublk_complete_rq(), blk_update_request() or blk_mq_end_request() runs bio->bi_end_io() callbacks 4. If this triggers fput() on file descriptor of ublk block device, the work may be deferred to current task's task work (see fput() implementation) 5. This eventually calls blkdev_release() from the same context 6. blkdev_release() tries to grab disk->open_mutex again 7. Deadlock: same task waiting for a mutex it already holds The fix is to run blk_update_request() and blk_mq_end_request() with bottom halves disabled. This forces blkdev_release() to run in kernel work-queue context instead of current task work context, and allows ublk server to make forward progress, and avoids the deadlock. Fixes: 71f28f3136af ("ublk_drv: add io_uring based userspace block driver") Link: https://github.com/ublk-org/ublksrv/issues/170 [1] Signed-off-by: Ming Lei Reviewed-by: Caleb Sander Mateos [axboe: rewrite comment in ublk] Signed-off-by: Jens Axboe [ The fix omits the change in __ublk_do_auto_buf_reg() since this function doesn't exist in 6.1. ] Signed-off-by: Ruohan Lan Signed-off-by: Greg Kroah-Hartman

drbd: fix "LOGIC BUG" in drbd_al_begin_io_nonblock()

2026-03-25T10:02:58+00:00

commit ab140365fb62c0bdab22b2f516aff563b2559e3b upstream. Even though we check that we "should" be able to do lc_get_cumulative() while holding the device->al_lock spinlock, it may still fail, if some other code path decided to do lc_try_lock() with bad timing. If that happened, we logged "LOGIC BUG for enr=...", but still did not return an error. The rest of the code now assumed that this request has references for the relevant activity log extents. The implcations are that during an active resync, mutual exclusivity of resync versus application IO is not guaranteed. And a potential crash at this point may not realizs that these extents could have been target of in-flight IO and would need to be resynced just in case. Also, once the request completes, it will give up activity log references it does not even hold, which will trigger a BUG_ON(refcnt == 0) in lc_put(). Fix: Do not crash the kernel for a condition that is harmless during normal operation: also catch "e->refcnt == 0", not only "e == NULL" when being noisy about "al_complete_io() called on inactive extent %u\n". And do not try to be smart and "guess" whether something will work, then be surprised when it does not. Deal with the fact that it may or may not work. If it does not, remember a possible "partially in activity log" state (only possible for requests that cross extent boundaries), and return an error code from drbd_al_begin_io_nonblock(). A latter call for the same request will then resume from where we left off. Cc: stable@vger.kernel.org Signed-off-by: Lars Ellenberg Signed-off-by: Christoph Böhmwalder Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

rnbd-srv: Zero the rsp buffer before using it

2026-03-04T12:20:13+00:00

[ Upstream commit 69d26698e4fd44935510553809007151b2fe4db5 ] Before using the data buffer to send back the response message, zero it completely. This prevents any stray bytes to be picked up by the client side when there the message is exchanged between different protocol versions. Signed-off-by: Md Haris Iqbal Signed-off-by: Jack Wang Signed-off-by: Grzegorz Prajsner Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

ublk: Validate SQE128 flag before accessing the cmd

2026-03-04T12:19:25+00:00

[ Upstream commit da7e4b75e50c087d2031a92f6646eb90f7045a67 ] ublk_ctrl_cmd_dump() accesses (header *)sqe->cmd before IO_URING_F_SQE128 flag check. This could cause out of boundary memory access. Move the SQE128 flag check earlier in ublk_ctrl_uring_cmd() to return -EINVAL immediately if the flag is not set. Fixes: 71f28f3136af ("ublk_drv: add io_uring based userspace block driver") Signed-off-by: Govindarajulu Varadarajan Reviewed-by: Caleb Sander Mateos Reviewed-by: Ming Lei Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

rbd: check for EOD after exclusive lock is ensured to be held

2026-02-11T12:37:19+00:00

commit bd3884a204c3b507e6baa9a4091aa927f9af5404 upstream. Similar to commit 870611e4877e ("rbd: get snapshot context after exclusive lock is ensured to be held"), move the "beyond EOD" check into the image request state machine so that it's performed after exclusive lock is ensured to be held. This avoids various race conditions which can arise when the image is shrunk under I/O (in practice, mostly readahead). In one such scenario rbd_assert(objno < rbd_dev->object_map_size); can be triggered if a close-to-EOD read gets queued right before the shrink is initiated and the EOD check is performed against an outdated mapping_size. After the resize is done on the server side and exclusive lock is (re)acquired bringing along the new (now shrunk) object map, the read starts going through the state machine and rbd_obj_may_exist() gets invoked on an object that is out of bounds of rbd_dev->object_map array. Cc: stable@vger.kernel.org Signed-off-by: Ilya Dryomov Reviewed-by: Dongsheng Yang Signed-off-by: Greg Kroah-Hartman

xen: make remove callback of xen driver void returned

2026-02-06T15:44:18+00:00

[ Upstream commit 7cffcade57a429667447c4f41d8414bbcf1b3aaa ] Since commit fc7a6209d571 ("bus: Make remove callback return void") forces bus_type::remove be void-returned, it doesn't make much sense for any bus based driver implementing remove callbalk to return non-void to its caller. This change is for xen bus based drivers. Acked-by: Juergen Gross Signed-off-by: Dawei Li Link: https://lore.kernel.org/r/TYCP286MB23238119AB4DF190997075C9CAE39@TYCP286MB2323.JPNP286.PROD.OUTLOOK.COM Signed-off-by: Juergen Gross Stable-dep-of: 901a5f309dab ("scsi: xen: scsiback: Fix potential memory leak in scsiback_remove()") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

floppy: fix for PAGE_SIZE != 4KB

2026-01-11T14:18:50+00:00

commit 82d20481024cbae2ea87fe8b86d12961bfda7169 upstream. For years I wondered why the floppy driver does not just work on sparc64, e.g: root@SUNW_375_0066:# disktype /dev/fd0 disktype: Can't open /dev/fd0: No such device or address [ 525.341906] disktype: attempt to access beyond end of device fd0: rw=0, sector=0, nr_sectors = 16 limit=8 [ 525.341991] floppy: error 10 while reading block 0 Turns out floppy.c __floppy_read_block_0 tries to read one page for the first test read to determine the disk size and thus fails if that is greater than 4k. Adjust minimum MAX_DISK_SIZE to PAGE_SIZE to fix floppy on sparc64 and likely all other PAGE_SIZE != 4KB configs. Cc: stable@vger.kernel.org Signed-off-by: René Rebe Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

block: rnbd-clt: Fix signedness bug in init_dev()

2026-01-11T14:18:49+00:00

[ Upstream commit 1ddb815fdfd45613c32e9bd1f7137428f298e541 ] The "dev->clt_device_id" variable is set using ida_alloc_max() which returns an int and in particular it returns negative error codes. Change the type from u32 to int to fix the error checking. Fixes: c9b5645fd8ca ("block: rnbd-clt: Fix leaked ID in init_dev()") Signed-off-by: Dan Carpenter Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin