Message-ID: <66f6bf69.050a0220.46d20.001a.GAE@google.com>
Date: Fri, 27 Sep 2024 07:21:29 -0700
From: syzbot <syzbot+c297885a2650fbdcfdc1@...kaller.appspotmail.com>
To: brauner@...nel.org, djwong@...nel.org, linux-fsdevel@...r.kernel.org, 
	linux-kernel@...r.kernel.org, linux-xfs@...r.kernel.org, 
	syzkaller-bugs@...glegroups.com
Subject: [syzbot] [iomap?] KASAN: use-after-free Read in iomap_read_inline_data

Hello,

syzbot found the following issue on:

HEAD commit:    88264981f208 Merge tag 'sched_ext-for-6.12' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10b5dca9980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e851828834875d6f
dashboard link: https://syzkaller.appspot.com/bug?extid=c297885a2650fbdcfdc1
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-88264981.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/df2a0a047a7a/vmlinux-88264981.xz
kernel image: https://storage.googleapis.com/syzbot-assets/bbdb25081712/bzImage-88264981.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c297885a2650fbdcfdc1@...kaller.appspotmail.com

loop0: detected capacity change from 0 to 32768
gfs2: fsid=syz:syz: Trying to join cluster "lock_nolock", "syz:syz"
gfs2: fsid=syz:syz: Now mounting FS (format 1801)...
gfs2: fsid=syz:syz.0: journal 0 mapped with 16 extents in 0ms
gfs2: fsid=syz:syz.0: first mount done, others may mount
==================================================================
BUG: KASAN: use-after-free in folio_fill_tail include/linux/highmem.h:577 [inline]
BUG: KASAN: use-after-free in iomap_read_inline_data+0x2bb/0x440 fs/iomap/buffered-io.c:354
Read of size 192 at addr ffff888000e800e8 by task syz.0.0/5123

CPU: 0 UID: 0 PID: 5123 Comm: syz.0.0 Not tainted 6.11.0-syzkaller-08481-g88264981f208 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105
 folio_fill_tail include/linux/highmem.h:577 [inline]
 iomap_read_inline_data+0x2bb/0x440 fs/iomap/buffered-io.c:354
 iomap_readpage_iter+0x2d6/0xba0 fs/iomap/buffered-io.c:382
 iomap_read_folio_iter fs/iomap/buffered-io.c:454 [inline]
 iomap_read_folio+0x532/0x8d0 fs/iomap/buffered-io.c:477
 gfs2_read_folio+0x12c/0x540 fs/gfs2/aops.c:454
 filemap_read_folio+0x14b/0x630 mm/filemap.c:2363
 do_read_cache_folio+0x3f5/0x850 mm/filemap.c:3821
 gfs2_internal_read+0x9d/0x4c0 fs/gfs2/aops.c:487
 read_rindex_entry fs/gfs2/rgrp.c:906 [inline]
 gfs2_ri_update+0x24a/0x1830 fs/gfs2/rgrp.c:1001
 gfs2_rindex_update+0x304/0x3d0 fs/gfs2/rgrp.c:1051
 init_inodes+0x24d/0x320 fs/gfs2/ops_fstype.c:892
 gfs2_fill_super+0x1c18/0x2500 fs/gfs2/ops_fstype.c:1249
 get_tree_bdev+0x3f7/0x570 fs/super.c:1635
 gfs2_get_tree+0x54/0x220 fs/gfs2/ops_fstype.c:1329
 vfs_get_tree+0x90/0x2b0 fs/super.c:1800
 do_new_mount+0x2be/0xb40 fs/namespace.c:3507
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4055 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4032
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2c5a77f69a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2c5b61ce68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f2c5b61cef0 RCX: 00007f2c5a77f69a
RDX: 00000000200002c0 RSI: 0000000020000100 RDI: 00007f2c5b61ceb0
RBP: 00000000200002c0 R08: 00007f2c5b61cef0 R09: 0000000000008c9b
R10: 0000000000008c9b R11: 0000000000000246 R12: 0000000020000100
R13: 00007f2c5b61ceb0 R14: 0000000000012760 R15: 0000000020000400
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x923 pfn:0xe80
flags: 0x7ff00000000000(node=0|zone=0|lastcpupid=0x7ff)
page_type: f0(buddy)
raw: 007ff00000000000 ffffea000000e808 ffffea0000004288 0000000000000000
raw: 0000000000000923 0000000000000000 00000000f0000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x48c40(GFP_NOFS|__GFP_NOFAIL|__GFP_COMP), pid 5123, tgid 5121 (syz.0.0), ts 142142458203, free_ts 142143773467
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_pages_noprof mm/mempolicy.c:2345 [inline]
 folio_alloc_noprof+0x128/0x180 mm/mempolicy.c:2352
 filemap_alloc_folio_noprof+0xdf/0x500 mm/filemap.c:1010
 __filemap_get_folio+0x446/0xbd0 mm/filemap.c:1952
 gfs2_getbuf+0x150/0x6a0 fs/gfs2/meta_io.c:132
 gfs2_meta_read+0x1e5/0x9b0 fs/gfs2/meta_io.c:261
 gfs2_meta_buffer+0x19a/0x410 fs/gfs2/meta_io.c:489
 gfs2_meta_inode_buffer fs/gfs2/meta_io.h:72 [inline]
 gfs2_inode_refresh+0xec/0x10b0 fs/gfs2/glops.c:478
 gfs2_instantiate+0x190/0x260 fs/gfs2/glock.c:468
 gfs2_glock_holder_ready fs/gfs2/glock.c:1345 [inline]
 gfs2_glock_wait+0x1df/0x2b0 fs/gfs2/glock.c:1365
 gfs2_glock_nq_init fs/gfs2/glock.h:238 [inline]
 gfs2_rindex_update+0x274/0x3d0 fs/gfs2/rgrp.c:1045
 init_inodes+0x24d/0x320 fs/gfs2/ops_fstype.c:892
 gfs2_fill_super+0x1c18/0x2500 fs/gfs2/ops_fstype.c:1249
page last free pid 80 tgid 80 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 free_unref_folios+0xf12/0x18d0 mm/page_alloc.c:2686
 shrink_folio_list+0x81fd/0x8cc0 mm/vmscan.c:1550
 evict_folios+0x549b/0x7b50 mm/vmscan.c:4583
 try_to_shrink_lruvec+0x9ab/0xbb0 mm/vmscan.c:4778
 shrink_one+0x3b9/0x850 mm/vmscan.c:4816
 shrink_many mm/vmscan.c:4879 [inline]
 lru_gen_shrink_node mm/vmscan.c:4957 [inline]
 shrink_node+0x3799/0x3de0 mm/vmscan.c:5937
 kswapd_shrink_node mm/vmscan.c:6765 [inline]
 balance_pgdat mm/vmscan.c:6957 [inline]
 kswapd+0x1ca3/0x3700 mm/vmscan.c:7226
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff888000e7ff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888000e80000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888000e80080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                          ^
 ffff888000e80100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888000e80180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================


---
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