CVE-2024-53170

In the Linux kernel, the following vulnerability has been resolved:

block: fix uaf for flush rq while iterating tags

blk_mq_clear_flush_rq_mapping() is not called during scsi probe, by

checking blk_queue_init_done(). However, QUEUE_FLAG_INIT_DONE is cleared

in del_gendisk by commit aec89dc5d421 ("block: keep q_usage_counter in

atomic mode after del_gendisk"), hence for disk like scsi, following

blk_mq_destroy_queue() will not clear flush rq from tags->rqs[] as well,

cause following uaf that is found by our syzkaller for v6.6:

==================================================================

BUG: KASAN: slab-use-after-free in blk_mq_find_and_get_req+0x16e/0x1a0 block/blk-mq-tag.c:261

Read of size 4 at addr ffff88811c969c20 by task kworker/1:2H/224909

CPU: 1 PID: 224909 Comm: kworker/1:2H Not tainted 6.6.0-ga836a5060850 #32

Workqueue: kblockd blk_mq_timeout_work

Call Trace:

__dump_stack lib/dump_stack.c:88 [inline]

dump_stack_lvl+0x91/0xf0 lib/dump_stack.c:106

print_address_description.constprop.0+0x66/0x300 mm/kasan/report.c:364

print_report+0x3e/0x70 mm/kasan/report.c:475

kasan_report+0xb8/0xf0 mm/kasan/report.c:588

blk_mq_find_and_get_req+0x16e/0x1a0 block/blk-mq-tag.c:261

bt_iter block/blk-mq-tag.c:288 [inline]

__sbitmap_for_each_set include/linux/sbitmap.h:295 [inline]

sbitmap_for_each_set include/linux/sbitmap.h:316 [inline]

bt_for_each+0x455/0x790 block/blk-mq-tag.c:325

blk_mq_queue_tag_busy_iter+0x320/0x740 block/blk-mq-tag.c:534

blk_mq_timeout_work+0x1a3/0x7b0 block/blk-mq.c:1673

process_one_work+0x7c4/0x1450 kernel/workqueue.c:2631

process_scheduled_works kernel/workqueue.c:2704 [inline]

worker_thread+0x804/0xe40 kernel/workqueue.c:2785

kthread+0x346/0x450 kernel/kthread.c:388

ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147

ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:293

Allocated by task 942:

kasan_save_stack+0x22/0x50 mm/kasan/common.c:45

kasan_set_track+0x25/0x30 mm/kasan/common.c:52

____kasan_kmalloc mm/kasan/common.c:374 [inline]

__kasan_kmalloc mm/kasan/common.c:383 [inline]

__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:380

kasan_kmalloc include/linux/kasan.h:198 [inline]

__do_kmalloc_node mm/slab_common.c:1007 [inline]

__kmalloc_node+0x69/0x170 mm/slab_common.c:1014

kmalloc_node include/linux/slab.h:620 [inline]

kzalloc_node include/linux/slab.h:732 [inline]

blk_alloc_flush_queue+0x144/0x2f0 block/blk-flush.c:499

blk_mq_alloc_hctx+0x601/0x940 block/blk-mq.c:3788

blk_mq_alloc_and_init_hctx+0x27f/0x330 block/blk-mq.c:4261

blk_mq_realloc_hw_ctxs+0x488/0x5e0 block/blk-mq.c:4294

blk_mq_init_allocated_queue+0x188/0x860 block/blk-mq.c:4350

blk_mq_init_queue_data block/blk-mq.c:4166 [inline]

blk_mq_init_queue+0x8d/0x100 block/blk-mq.c:4176

scsi_alloc_sdev+0x843/0xd50 drivers/scsi/scsi_scan.c:335

scsi_probe_and_add_lun+0x77c/0xde0 drivers/scsi/scsi_scan.c:1189

__scsi_scan_target+0x1fc/0x5a0 drivers/scsi/scsi_scan.c:1727

scsi_scan_channel drivers/scsi/scsi_scan.c:1815 [inline]

scsi_scan_channel+0x14b/0x1e0 drivers/scsi/scsi_scan.c:1791

scsi_scan_host_selected+0x2fe/0x400 drivers/scsi/scsi_scan.c:1844

scsi_scan+0x3a0/0x3f0 drivers/scsi/scsi_sysfs.c:151

store_scan+0x2a/0x60 drivers/scsi/scsi_sysfs.c:191

dev_attr_store+0x5c/0x90 drivers/base/core.c:2388

sysfs_kf_write+0x11c/0x170 fs/sysfs/file.c:136

kernfs_fop_write_iter+0x3fc/0x610 fs/kernfs/file.c:338

call_write_iter include/linux/fs.h:2083 [inline]

new_sync_write+0x1b4/0x2d0 fs/read_write.c:493

vfs_write+0x76c/0xb00 fs/read_write.c:586

ksys_write+0x127/0x250 fs/read_write.c:639

do_syscall_x64 arch/x86/entry/common.c:51 [inline]

do_syscall_64+0x70/0x120 arch/x86/entry/common.c:81

entry_SYSCALL_64_after_hwframe+0x78/0xe2

Freed by task 244687:

kasan_save_stack+0x22/0x50 mm/kasan/common.c:45

kasan_set_track+0x25/0x30 mm/kasan/common.c:52

kasan_save_free_info+0x2b/0x50 mm/kasan/generic.c:522

____kasan_slab_free mm/kasan/common.c:236 [inline]

__kasan_slab_free+0x12a/0x1b0 mm/kasan/common.c:244

kasan_slab_free include/linux/kasan.h:164 [in

---truncated---