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Qu Wenruo 724d8042ce btrfs: always do the basic checks for btrfs_qgroup_inherit structure
[BUG]
Syzbot reports the following regression detected by KASAN:

  BUG: KASAN: slab-out-of-bounds in btrfs_qgroup_inherit+0x42e/0x2e20 fs/btrfs/qgroup.c:3277
  Read of size 8 at addr ffff88814628ca50 by task syz-executor318/5171

  CPU: 0 PID: 5171 Comm: syz-executor318 Not tainted 6.10.0-rc2-syzkaller-00010-g2ab795141095 #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
  Call Trace:
   <TASK>
   __dump_stack lib/dump_stack.c:88 [inline]
   dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
   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
   btrfs_qgroup_inherit+0x42e/0x2e20 fs/btrfs/qgroup.c:3277
   create_pending_snapshot+0x1359/0x29b0 fs/btrfs/transaction.c:1854
   create_pending_snapshots+0x195/0x1d0 fs/btrfs/transaction.c:1922
   btrfs_commit_transaction+0xf20/0x3740 fs/btrfs/transaction.c:2382
   create_snapshot+0x6a1/0x9e0 fs/btrfs/ioctl.c:875
   btrfs_mksubvol+0x58f/0x710 fs/btrfs/ioctl.c:1029
   btrfs_mksnapshot+0xb5/0xf0 fs/btrfs/ioctl.c:1075
   __btrfs_ioctl_snap_create+0x387/0x4b0 fs/btrfs/ioctl.c:1340
   btrfs_ioctl_snap_create_v2+0x1f2/0x3a0 fs/btrfs/ioctl.c:1422
   btrfs_ioctl+0x99e/0xc60
   vfs_ioctl fs/ioctl.c:51 [inline]
   __do_sys_ioctl fs/ioctl.c:907 [inline]
   __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
   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: 0033:0x7fcbf1992509
  RSP: 002b:00007fcbf1928218 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  RAX: ffffffffffffffda RBX: 00007fcbf1a1f618 RCX: 00007fcbf1992509
  RDX: 0000000020000280 RSI: 0000000050009417 RDI: 0000000000000003
  RBP: 00007fcbf1a1f610 R08: 00007ffea1298e97 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 00007fcbf19eb660
  R13: 00000000200002b8 R14: 00007fcbf19e60c0 R15: 0030656c69662f2e
   </TASK>

And it also pinned it down to commit b5357cb268 ("btrfs: qgroup: do not
check qgroup inherit if qgroup is disabled").

[CAUSE]
That offending commit skips the whole qgroup inherit check if qgroup is
not enabled.

But that also skips the very basic checks like
num_ref_copies/num_excl_copies and the structure size checks.

Meaning if a qgroup enable/disable race is happening at the background,
and we pass a btrfs_qgroup_inherit structure when the qgroup is
disabled, the check would be completely skipped.

Then at the time of transaction commitment, qgroup is re-enabled and
btrfs_qgroup_inherit() is going to use the incorrect structure and
causing the above KASAN error.

[FIX]
Make btrfs_qgroup_check_inherit() only skip the source qgroup checks.
So that even if invalid btrfs_qgroup_inherit structure is passed in, we
can still reject invalid ones no matter if qgroup is enabled or not.

Furthermore we do already have an extra safety inside
btrfs_qgroup_inherit(), which would just ignore invalid qgroup sources,
so even if we only skip the qgroup source check we're still safe.

Reported-by: syzbot+a0d1f7e26910be4dc171@syzkaller.appspotmail.com
Fixes: b5357cb268 ("btrfs: qgroup: do not check qgroup inherit if qgroup is disabled")
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Jeongjun Park <aha310510@gmail.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-07-02 19:14:36 +02:00
arch powerpc fixes for 6.9 #4 2024-05-05 10:44:04 -07:00
block bio: Export bio_add_folio_nofail to modules 2024-05-07 21:31:10 +02:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto This push fixes a regression that broke iwd as well as a divide by 2024-03-25 10:48:23 -07:00
Documentation Char/Misc driver fixes for 6.9-rc7 2024-05-05 10:08:52 -07:00
drivers Reapply "drm/qxl: simplify qxl_fence_wait" 2024-05-06 13:28:59 -07:00
fs btrfs: always do the basic checks for btrfs_qgroup_inherit structure 2024-07-02 19:14:36 +02:00
include btrfs: add tracepoints for extent map shrinker events 2024-05-07 21:31:07 +02:00
init Rust fixes for v6.9 2024-04-27 12:11:55 -07:00
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mm mm/slub: avoid zeroing outside-object freepointer for single free 2024-05-01 17:28:56 +02:00
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scripts Rust fixes for v6.9 2024-04-27 12:11:55 -07:00
security security: Place security_path_post_mknod() where the original IMA call was 2024-04-03 10:21:32 -07:00
sound ALSA: hda/realtek: Fix build error without CONFIG_PM 2024-05-02 08:25:06 +02:00
tools cxl fix for v6.9-rc7 2024-05-03 16:21:05 -07:00
usr Kbuild updates for v6.8 2024-01-18 17:57:07 -08:00
virt KVM: Drop unused @may_block param from gfn_to_pfn_cache_invalidate_start() 2024-04-11 12:58:53 -07:00
.clang-format clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig
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.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
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.mailmap bpf-for-netdev 2024-04-26 17:36:53 -07:00
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COPYING
CREDITS MAINTAINERS: Drop Gustavo Pimentel as PCI DWC Maintainer 2024-03-27 13:41:02 -05:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Including fixes from bpf. 2024-05-02 08:51:47 -07:00
Makefile Linux 6.9-rc7 2024-05-05 14:06:01 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
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There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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There are various text files in the Documentation/ subdirectory,
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Please read the Documentation/process/changes.rst file, as it contains the
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