Hi,
在 2024/11/19 23:34, Zach Wade 写道:
This reverts commit bc3b1e9e7c50e1de0f573eea3871db61dd4787de.
The bic is associated with sync_bfqq, and bfq_release_process_ref cannot
be put into bfq_put_cooperator.
This descrption is not clear to me.
kasan report:
[ 400.347277] ==================================================================
[ 400.347287] BUG: KASAN: slab-use-after-free in bic_set_bfqq+0x200/0x230
[ 400.347420] Read of size 8 at addr ffff88881cab7d60 by task dockerd/5800
[ 400.347430]
[ 400.347436] CPU: 24 UID: 0 PID: 5800 Comm: dockerd Kdump: loaded Tainted: G E 6.12.0 #32
[ 400.347450] Tainted: [E]=UNSIGNED_MODULE
[ 400.347454] Hardware name: VMware, Inc. VMware20,1/440BX Desktop Reference Platform, BIOS VMW201.00V.20192059.B64.2207280713 07/28/2022
[ 400.347460] Call Trace:
[ 400.347464] <TASK>
[ 400.347468] dump_stack_lvl+0x5d/0x80
[ 400.347490] print_report+0x174/0x505
[ 400.347521] kasan_report+0xe0/0x160
[ 400.347541] bic_set_bfqq+0x200/0x230
[ 400.347549] bfq_bic_update_cgroup+0x419/0x740
[ 400.347560] bfq_bio_merge+0x133/0x320
[ 400.347584] blk_mq_submit_bio+0x1761/0x1e20
[ 400.347625] __submit_bio+0x28b/0x7b0
[ 400.347664] submit_bio_noacct_nocheck+0x6b2/0xd30
[ 400.347690] iomap_readahead+0x50c/0x680
[ 400.347731] read_pages+0x17f/0x9c0
[ 400.347785] page_cache_ra_unbounded+0x366/0x4a0
[ 400.347795] filemap_fault+0x83d/0x2340
[ 400.347819] __xfs_filemap_fault+0x11a/0x7d0 [xfs]
[ 400.349256] __do_fault+0xf1/0x610
[ 400.349270] do_fault+0x977/0x11a0
[ 400.349281] __handle_mm_fault+0x5d1/0x850
[ 400.349314] handle_mm_fault+0x1f8/0x560
[ 400.349324] do_user_addr_fault+0x324/0x970
[ 400.349337] exc_page_fault+0x76/0xf0
[ 400.349350] asm_exc_page_fault+0x26/0x30
[ 400.349360] RIP: 0033:0x55a480d77375
[ 400.349384] Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 49 3b 66 10 0f 86 ae 02 00 00 55 48 89 e5 48 83 ec 58 48 8b 10 <83> 7a 10 00 0f 84 27 02 00 00 44 0f b6 42 28 44 0f b6 4a 29 41 80
[ 400.349392] RSP: 002b:00007f18c37fd8b8 EFLAGS: 00010216
[ 400.349401] RAX: 00007f18c37fd9d0 RBX: 0000000000000000 RCX: 0000000000000000
[ 400.349407] RDX: 000055a484407d38 RSI: 000000c000e8b0c0 RDI: 0000000000000000
[ 400.349412] RBP: 00007f18c37fd910 R08: 000055a484017f60 R09: 000055a484066f80
[ 400.349417] R10: 0000000000194000 R11: 0000000000000005 R12: 0000000000000008
[ 400.349422] R13: 0000000000000000 R14: 000000c000476a80 R15: 0000000000000000
[ 400.349430] </TASK>
[ 400.349452]
[ 400.349454] Allocated by task 5800:
[ 400.349459] kasan_save_stack+0x30/0x50
[ 400.349469] kasan_save_track+0x14/0x30
[ 400.349475] __kasan_slab_alloc+0x89/0x90
[ 400.349482] kmem_cache_alloc_node_noprof+0xdc/0x2a0
[ 400.349492] bfq_get_queue+0x1ef/0x1100
[ 400.349502] __bfq_get_bfqq_handle_split+0x11a/0x510
[ 400.349511] bfq_insert_requests+0xf55/0x9030
[ 400.349519] blk_mq_flush_plug_list+0x446/0x14c0
[ 400.349527] __blk_flush_plug+0x27c/0x4e0
[ 400.349534] blk_finish_plug+0x52/0xa0
[ 400.349540] _xfs_buf_ioapply+0x739/0xc30 [xfs]
[ 400.350246] __xfs_buf_submit+0x1b2/0x640 [xfs]
[ 400.350967] xfs_buf_read_map+0x306/0xa20 [xfs]
[ 400.351672] xfs_trans_read_buf_map+0x285/0x7d0 [xfs]
[ 400.352386] xfs_imap_to_bp+0x107/0x270 [xfs]
[ 400.353077] xfs_iget+0x70d/0x1eb0 [xfs]
[ 400.353786] xfs_lookup+0x2ca/0x3a0 [xfs]
[ 400.354506] xfs_vn_lookup+0x14e/0x1a0 [xfs]
[ 400.355197] __lookup_slow+0x19c/0x340
[ 400.355204] lookup_one_unlocked+0xfc/0x120
[ 400.355211] ovl_lookup_single+0x1b3/0xcf0 [overlay]
[ 400.355255] ovl_lookup_layer+0x316/0x490 [overlay]
[ 400.355295] ovl_lookup+0x844/0x1fd0 [overlay]
[ 400.355351] lookup_one_qstr_excl+0xef/0x150
[ 400.355357] do_unlinkat+0x22a/0x620
[ 400.355366] __x64_sys_unlinkat+0x109/0x1e0
[ 400.355375] do_syscall_64+0x82/0x160
[ 400.355384] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 400.355393]
[ 400.355395] Freed by task 5800:
[ 400.355400] kasan_save_stack+0x30/0x50
[ 400.355407] kasan_save_track+0x14/0x30
[ 400.355413] kasan_save_free_info+0x3b/0x70
[ 400.355422] __kasan_slab_free+0x4f/0x70
[ 400.355429] kmem_cache_free+0x176/0x520
[ 400.355438] bfq_put_queue+0x67e/0x980
[ 400.355447] bfq_bic_update_cgroup+0x407/0x740
[ 400.355454] bfq_bio_merge+0x133/0x320
[ 400.355460] blk_mq_submit_bio+0x1761/0x1e20
[ 400.355467] __submit_bio+0x28b/0x7b0
[ 400.355473] submit_bio_noacct_nocheck+0x6b2/0xd30
[ 400.355480] iomap_readahead+0x50c/0x680
[ 400.355490] read_pages+0x17f/0x9c0
[ 400.355498] page_cache_ra_unbounded+0x366/0x4a0
[ 400.355505] filemap_fault+0x83d/0x2340
[ 400.355514] __xfs_filemap_fault+0x11a/0x7d0 [xfs]
[ 400.356204] __do_fault+0xf1/0x610
[ 400.356213] do_fault+0x977/0x11a0
[ 400.356221] __handle_mm_fault+0x5d1/0x850
[ 400.356230] handle_mm_fault+0x1f8/0x560
[ 400.356238] do_user_addr_fault+0x324/0x970
[ 400.356248] exc_page_fault+0x76/0xf0
[ 400.356258] asm_exc_page_fault+0x26/0x30
I get it now, the root cause is that bfqq is freed by
bfq_release_process_ref(), and later bic_set_bfqq() will trigger
above uaf.
LGTM
Reviewed-by: Yu Kuai <yukuai3@xxxxxxxxxx>
[ 400.356266]
[ 400.356269] The buggy address belongs to the object at ffff88881cab7bc0
which belongs to the cache bfq_queue of size 576
[ 400.356276] The buggy address is located 416 bytes inside of
freed 576-byte region [ffff88881cab7bc0, ffff88881cab7e00)
[ 400.356285]
[ 400.356287] The buggy address belongs to the physical page:
[ 400.356292] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88881cab0b00 pfn:0x81cab0
[ 400.356300] head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
[ 400.356323] flags: 0x50000000000040(head|node=1|zone=2)
[ 400.356331] page_type: f5(slab)
[ 400.356340] raw: 0050000000000040 ffff88880a00c280 dead000000000122 0000000000000000
[ 400.356347] raw: ffff88881cab0b00 00000000802e0025 00000001f5000000 0000000000000000
[ 400.356354] head: 0050000000000040 ffff88880a00c280 dead000000000122 0000000000000000
[ 400.356359] head: ffff88881cab0b00 00000000802e0025 00000001f5000000 0000000000000000
[ 400.356365] head: 0050000000000003 ffffea002072ac01 ffffffffffffffff 0000000000000000
[ 400.356370] head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
[ 400.356378] page dumped because: kasan: bad access detected
[ 400.356381]
[ 400.356383] Memory state around the buggy address:
[ 400.356387] ffff88881cab7c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 400.356392] ffff88881cab7c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 400.356397] >ffff88881cab7d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 400.356400] ^
[ 400.356405] ffff88881cab7d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 400.356409] ffff88881cab7e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 400.356413] ==================================================================
Fixes: bc3b1e9e7c50 ("block, bfq: merge bfq_release_process_ref() into bfq_put_cooperator()")
Signed-off-by: Zach Wade <zachwade.k@xxxxxxxxx>
Cc: Ding Hui <dinghui@xxxxxxxxxxxxxx>
---
block/bfq-cgroup.c | 1 +
block/bfq-iosched.c | 6 ++++--
2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index e831aedb4643..9fb9f3533150 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -736,6 +736,7 @@ static void bfq_sync_bfqq_move(struct bfq_data *bfqd,
*/
bfq_put_cooperator(sync_bfqq);
bic_set_bfqq(bic, NULL, true, act_idx);
+ bfq_release_process_ref(bfqd, sync_bfqq);
}
}
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 0747d9d0e48c..28c2bb06e859 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5434,8 +5434,6 @@ void bfq_put_cooperator(struct bfq_queue *bfqq)
bfq_put_queue(__bfqq);
__bfqq = next;
}
-
- bfq_release_process_ref(bfqq->bfqd, bfqq);
}
static void bfq_exit_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq)
@@ -5448,6 +5446,8 @@ static void bfq_exit_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq)
bfq_log_bfqq(bfqd, bfqq, "exit_bfqq: %p, %d", bfqq, bfqq->ref);
bfq_put_cooperator(bfqq);
+
+ bfq_release_process_ref(bfqd, bfqq);
}
static void bfq_exit_icq_bfqq(struct bfq_io_cq *bic, bool is_sync,
@@ -6734,6 +6734,8 @@ bfq_split_bfqq(struct bfq_io_cq *bic, struct bfq_queue *bfqq)
bic_set_bfqq(bic, NULL, true, bfqq->actuator_idx);
bfq_put_cooperator(bfqq);
+
+ bfq_release_process_ref(bfqq->bfqd, bfqq);
return NULL;
}
