CVE-2023-53348: In the Linux kernel, the following vulnerability has been resolved:  btrfs: fix deadlock when aborting transaction during relocation with scrub  Before relocating a block group we pause scrub, then do the relocation and then unpause scrub. The relocation process requires starting and committing a transaction, and if we have a failure in the critical section of the transaction commit path (transaction state >= TRANS_STATE_COMMIT_START), we will deadlock if there is a paused scrub.  That results in stack traces like the following:    [42.479] BTRFS info (device sdc): relocating block group 53876686848 flags metadata|raid6   [42.936] BTRFS warning (device sdc): Skipping commit of aborted transaction.   [42.936] ------------[ cut here ]------------   [42.936] BTRFS: Transaction aborted (error -28)   [42.936] WARNING: CPU: 11 PID: 346822 at fs/btrfs/transaction.c:1977 btrfs_commit_transaction+0xcc8/0xeb0 [btrfs]   [42.936] Modules linked in: dm_flakey dm_mod loop btrfs (...)   [42.936] CPU: 11 PID: 346822 Comm: btrfs Tainted: G        W          6.3.0-rc2-btrfs-next-127+ #1   [42.936] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014   [42.936] RIP: 0010:btrfs_commit_transaction+0xcc8/0xeb0 [btrfs]   [42.936] Code: ff ff 45 8b (...)   [42.936] RSP: 0018:ffffb58649633b48 EFLAGS: 00010282   [42.936] RAX: 0000000000000000 RBX: ffff8be6ef4d5bd8 RCX: 0000000000000000   [42.936] RDX: 0000000000000002 RSI: ffffffffb35e7782 RDI: 00000000ffffffff   [42.936] RBP: ffff8be6ef4d5c98 R08: 0000000000000000 R09: ffffb586496339e8   [42.936] R10: 0000000000000001 R11: 0000000000000001 R12: ffff8be6d38c7c00   [42.936] R13: 00000000ffffffe4 R14: ffff8be6c268c000 R15: ffff8be6ef4d5cf0   [42.936] FS:  00007f381a82b340(0000) GS:ffff8beddfcc0000(0000) knlGS:0000000000000000   [42.936] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033   [42.936] CR2: 00007f1e35fb7638 CR3: 0000000117680006 CR4: 0000000000370ee0   [42.936] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000   [42.936] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400   [42.936] Call Trace:   [42.936]  <TASK>   [42.936]  ? start_transaction+0xcb/0x610 [btrfs]   [42.936]  prepare_to_relocate+0x111/0x1a0 [btrfs]   [42.936]  relocate_block_group+0x57/0x5d0 [btrfs]   [42.936]  ? btrfs_wait_nocow_writers+0x25/0xb0 [btrfs]   [42.936]  btrfs_relocate_block_group+0x248/0x3c0 [btrfs]   [42.936]  ? __pfx_autoremove_wake_function+0x10/0x10   [42.936]  btrfs_relocate_chunk+0x3b/0x150 [btrfs]   [42.936]  btrfs_balance+0x8ff/0x11d0 [btrfs]   [42.936]  ? __kmem_cache_alloc_node+0x14a/0x410   [42.936]  btrfs_ioctl+0x2334/0x32c0 [btrfs]   [42.937]  ? mod_objcg_state+0xd2/0x360   [42.937]  ? refill_obj_stock+0xb0/0x160   [42.937]  ? seq_release+0x25/0x30   [42.937]  ? __rseq_handle_notify_resume+0x3b5/0x4b0   [42.937]  ? percpu_counter_add_batch+0x2e/0xa0   [42.937]  ? __x64_sys_ioctl+0x88/0xc0   [42.937]  __x64_sys_ioctl+0x88/0xc0   [42.937]  do_syscall_64+0x38/0x90   [42.937]  entry_SYSCALL_64_after_hwframe+0x72/0xdc   [42.937] RIP: 0033:0x7f381a6ffe9b   [42.937] Code: 00 48 89 44 24 (...)   [42.937] RSP: 002b:00007ffd45ecf060 EFLAGS: 00000246 ORIG_RAX: 0000000000000010   [42.937] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f381a6ffe9b   [42.937] RDX: 00007ffd45ecf150 RSI: 00000000c4009420 RDI: 0000000000000003   [42.937] RBP: 0000000000000003 R08: 0000000000000013 R09: 0000000000000000   [42.937] R10: 00007f381a60c878 R11: 0000000000000246 R12: 00007ffd45ed0423   [42.937] R13: 00007ffd45ecf150 R14: 0000000000000000 R15: 00007ffd45ecf148   [42.937]  </TASK>   [42.937] ---[ end trace 0000000000000000 ]---   [42.937] BTRFS: error (device sdc: state A) in cleanup_transaction:1977: errno=-28 No space left   [59.196] INFO: task btrfs:346772 blocked for more than 120 seconds.   [59.196]       Tainted: G        W          6.3.0-rc2-btrfs-next-127+ #1   [59.196] "echo 0 > /proc/sys/kernel/hung_ ---truncated---