From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
patches@lists.linux.dev, Tejun Heo <tj@kernel.org>,
"Christian A. Ehrhardt" <lk@c--e.de>, stable <stable@kernel.org>
Subject: [PATCH 4.9 20/44] kernfs: fix use-after-free in __kernfs_remove
Date: Wed, 2 Nov 2022 03:35:06 +0100 [thread overview]
Message-ID: <20221102022049.767876064@linuxfoundation.org> (raw)
In-Reply-To: <20221102022049.017479464@linuxfoundation.org>
From: Christian A. Ehrhardt <lk@c--e.de>
commit 4abc99652812a2ddf932f137515d5c5a04723538 upstream.
Syzkaller managed to trigger concurrent calls to
kernfs_remove_by_name_ns() for the same file resulting in
a KASAN detected use-after-free. The race occurs when the root
node is freed during kernfs_drain().
To prevent this acquire an additional reference for the root
of the tree that is removed before calling __kernfs_remove().
Found by syzkaller with the following reproducer (slab_nomerge is
required):
syz_mount_image$ext4(0x0, &(0x7f0000000100)='./file0\x00', 0x100000, 0x0, 0x0, 0x0, 0x0)
r0 = openat(0xffffffffffffff9c, &(0x7f0000000080)='/proc/self/exe\x00', 0x0, 0x0)
close(r0)
pipe2(&(0x7f0000000140)={0xffffffffffffffff, <r1=>0xffffffffffffffff}, 0x800)
mount$9p_fd(0x0, &(0x7f0000000040)='./file0\x00', &(0x7f00000000c0), 0x408, &(0x7f0000000280)={'trans=fd,', {'rfdno', 0x3d, r0}, 0x2c, {'wfdno', 0x3d, r1}, 0x2c, {[{@cache_loose}, {@mmap}, {@loose}, {@loose}, {@mmap}], [{@mask={'mask', 0x3d, '^MAY_EXEC'}}, {@fsmagic={'fsmagic', 0x3d, 0x10001}}, {@dont_hash}]}})
Sample report:
==================================================================
BUG: KASAN: use-after-free in kernfs_type include/linux/kernfs.h:335 [inline]
BUG: KASAN: use-after-free in kernfs_leftmost_descendant fs/kernfs/dir.c:1261 [inline]
BUG: KASAN: use-after-free in __kernfs_remove.part.0+0x843/0x960 fs/kernfs/dir.c:1369
Read of size 2 at addr ffff8880088807f0 by task syz-executor.2/857
CPU: 0 PID: 857 Comm: syz-executor.2 Not tainted 6.0.0-rc3-00363-g7726d4c3e60b #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x6e/0x91 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:317 [inline]
print_report.cold+0x5e/0x5e5 mm/kasan/report.c:433
kasan_report+0xa3/0x130 mm/kasan/report.c:495
kernfs_type include/linux/kernfs.h:335 [inline]
kernfs_leftmost_descendant fs/kernfs/dir.c:1261 [inline]
__kernfs_remove.part.0+0x843/0x960 fs/kernfs/dir.c:1369
__kernfs_remove fs/kernfs/dir.c:1356 [inline]
kernfs_remove_by_name_ns+0x108/0x190 fs/kernfs/dir.c:1589
sysfs_slab_add+0x133/0x1e0 mm/slub.c:5943
__kmem_cache_create+0x3e0/0x550 mm/slub.c:4899
create_cache mm/slab_common.c:229 [inline]
kmem_cache_create_usercopy+0x167/0x2a0 mm/slab_common.c:335
p9_client_create+0xd4d/0x1190 net/9p/client.c:993
v9fs_session_init+0x1e6/0x13c0 fs/9p/v9fs.c:408
v9fs_mount+0xb9/0xbd0 fs/9p/vfs_super.c:126
legacy_get_tree+0xf1/0x200 fs/fs_context.c:610
vfs_get_tree+0x85/0x2e0 fs/super.c:1530
do_new_mount fs/namespace.c:3040 [inline]
path_mount+0x675/0x1d00 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__x64_sys_mount+0x282/0x300 fs/namespace.c:3568
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f725f983aed
Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f725f0f7028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f725faa3f80 RCX: 00007f725f983aed
RDX: 00000000200000c0 RSI: 0000000020000040 RDI: 0000000000000000
RBP: 00007f725f9f419c R08: 0000000020000280 R09: 0000000000000000
R10: 0000000000000408 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000006 R14: 00007f725faa3f80 R15: 00007f725f0d7000
</TASK>
Allocated by task 855:
kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:45 [inline]
set_alloc_info mm/kasan/common.c:437 [inline]
__kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:470
kasan_slab_alloc include/linux/kasan.h:224 [inline]
slab_post_alloc_hook mm/slab.h:727 [inline]
slab_alloc_node mm/slub.c:3243 [inline]
slab_alloc mm/slub.c:3251 [inline]
__kmem_cache_alloc_lru mm/slub.c:3258 [inline]
kmem_cache_alloc+0xbf/0x200 mm/slub.c:3268
kmem_cache_zalloc include/linux/slab.h:723 [inline]
__kernfs_new_node+0xd4/0x680 fs/kernfs/dir.c:593
kernfs_new_node fs/kernfs/dir.c:655 [inline]
kernfs_create_dir_ns+0x9c/0x220 fs/kernfs/dir.c:1010
sysfs_create_dir_ns+0x127/0x290 fs/sysfs/dir.c:59
create_dir lib/kobject.c:63 [inline]
kobject_add_internal+0x24a/0x8d0 lib/kobject.c:223
kobject_add_varg lib/kobject.c:358 [inline]
kobject_init_and_add+0x101/0x160 lib/kobject.c:441
sysfs_slab_add+0x156/0x1e0 mm/slub.c:5954
__kmem_cache_create+0x3e0/0x550 mm/slub.c:4899
create_cache mm/slab_common.c:229 [inline]
kmem_cache_create_usercopy+0x167/0x2a0 mm/slab_common.c:335
p9_client_create+0xd4d/0x1190 net/9p/client.c:993
v9fs_session_init+0x1e6/0x13c0 fs/9p/v9fs.c:408
v9fs_mount+0xb9/0xbd0 fs/9p/vfs_super.c:126
legacy_get_tree+0xf1/0x200 fs/fs_context.c:610
vfs_get_tree+0x85/0x2e0 fs/super.c:1530
do_new_mount fs/namespace.c:3040 [inline]
path_mount+0x675/0x1d00 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__x64_sys_mount+0x282/0x300 fs/namespace.c:3568
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Freed by task 857:
kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
kasan_set_track+0x21/0x30 mm/kasan/common.c:45
kasan_set_free_info+0x20/0x40 mm/kasan/generic.c:370
____kasan_slab_free mm/kasan/common.c:367 [inline]
____kasan_slab_free mm/kasan/common.c:329 [inline]
__kasan_slab_free+0x108/0x190 mm/kasan/common.c:375
kasan_slab_free include/linux/kasan.h:200 [inline]
slab_free_hook mm/slub.c:1754 [inline]
slab_free_freelist_hook mm/slub.c:1780 [inline]
slab_free mm/slub.c:3534 [inline]
kmem_cache_free+0x9c/0x340 mm/slub.c:3551
kernfs_put.part.0+0x2b2/0x520 fs/kernfs/dir.c:547
kernfs_put+0x42/0x50 fs/kernfs/dir.c:521
__kernfs_remove.part.0+0x72d/0x960 fs/kernfs/dir.c:1407
__kernfs_remove fs/kernfs/dir.c:1356 [inline]
kernfs_remove_by_name_ns+0x108/0x190 fs/kernfs/dir.c:1589
sysfs_slab_add+0x133/0x1e0 mm/slub.c:5943
__kmem_cache_create+0x3e0/0x550 mm/slub.c:4899
create_cache mm/slab_common.c:229 [inline]
kmem_cache_create_usercopy+0x167/0x2a0 mm/slab_common.c:335
p9_client_create+0xd4d/0x1190 net/9p/client.c:993
v9fs_session_init+0x1e6/0x13c0 fs/9p/v9fs.c:408
v9fs_mount+0xb9/0xbd0 fs/9p/vfs_super.c:126
legacy_get_tree+0xf1/0x200 fs/fs_context.c:610
vfs_get_tree+0x85/0x2e0 fs/super.c:1530
do_new_mount fs/namespace.c:3040 [inline]
path_mount+0x675/0x1d00 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__x64_sys_mount+0x282/0x300 fs/namespace.c:3568
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
The buggy address belongs to the object at ffff888008880780
which belongs to the cache kernfs_node_cache of size 128
The buggy address is located 112 bytes inside of
128-byte region [ffff888008880780, ffff888008880800)
The buggy address belongs to the physical page:
page:00000000732833f8 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x8880
flags: 0x100000000000200(slab|node=0|zone=1)
raw: 0100000000000200 0000000000000000 dead000000000122 ffff888001147280
raw: 0000000000000000 0000000000150015 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888008880680: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
ffff888008880700: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff888008880780: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888008880800: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
ffff888008880880: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================
Acked-by: Tejun Heo <tj@kernel.org>
Cc: stable <stable@kernel.org> # -rc3
Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
Link: https://lore.kernel.org/r/20220913121723.691454-1-lk@c--e.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/kernfs/dir.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -1410,8 +1410,11 @@ int kernfs_remove_by_name_ns(struct kern
mutex_lock(&kernfs_mutex);
kn = kernfs_find_ns(parent, name, ns);
- if (kn)
+ if (kn) {
+ kernfs_get(kn);
__kernfs_remove(kn);
+ kernfs_put(kn);
+ }
mutex_unlock(&kernfs_mutex);
next prev parent reply other threads:[~2022-11-02 3:44 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-02 2:34 [PATCH 4.9 00/44] 4.9.332-rc1 review Greg Kroah-Hartman
2022-11-02 2:34 ` [PATCH 4.9 01/44] ocfs2: clear dinode links count in case of error Greg Kroah-Hartman
2022-11-02 2:34 ` [PATCH 4.9 02/44] ocfs2: fix BUG when iput after ocfs2_mknod fails Greg Kroah-Hartman
2022-11-02 2:34 ` [PATCH 4.9 03/44] ata: ahci-imx: Fix MODULE_ALIAS Greg Kroah-Hartman
2022-11-02 2:34 ` [PATCH 4.9 04/44] ata: ahci: Match EM_MAX_SLOTS with SATA_PMP_MAX_PORTS Greg Kroah-Hartman
2022-11-02 2:34 ` [PATCH 4.9 05/44] arm64: errata: Remove AES hwcap for COMPAT tasks Greg Kroah-Hartman
2022-11-02 2:34 ` [PATCH 4.9 06/44] HID: magicmouse: Do not set BTN_MOUSE on double report Greg Kroah-Hartman
2022-11-02 2:34 ` [PATCH 4.9 07/44] net/atm: fix proc_mpc_write incorrect return value Greg Kroah-Hartman
2022-11-02 2:34 ` [PATCH 4.9 08/44] net: hns: fix possible memory leak in hnae_ae_register() Greg Kroah-Hartman
2022-11-02 2:34 ` [PATCH 4.9 09/44] [PATCH v3] ACPI: video: Force backlight native for more TongFang devices Greg Kroah-Hartman
2022-11-02 2:34 ` [PATCH 4.9 10/44] ALSA: Use del_timer_sync() before freeing timer Greg Kroah-Hartman
2022-11-02 2:34 ` [PATCH 4.9 11/44] ALSA: au88x0: use explicitly signed char Greg Kroah-Hartman
2022-11-02 2:34 ` [PATCH 4.9 12/44] USB: add RESET_RESUME quirk for NVIDIA Jetson devices in RCM Greg Kroah-Hartman
2022-11-02 2:34 ` [PATCH 4.9 13/44] usb: bdc: change state when port disconnected Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 14/44] xhci: Remove device endpoints from bandwidth list when freeing the device Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 15/44] tools: iio: iio_utils: fix digit calculation Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 16/44] fbdev: smscufx: Fix several use-after-free bugs Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 17/44] mac802154: Fix LQI recording Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 18/44] drm/msm/hdmi: fix memory corruption with too many bridges Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 19/44] mmc: core: Fix kernel panic when remove non-standard SDIO card Greg Kroah-Hartman
2022-11-02 2:35 ` Greg Kroah-Hartman [this message]
2022-11-02 2:35 ` [PATCH 4.9 21/44] s390/futex: add missing EX_TABLE entry to __futex_atomic_op() Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 22/44] Xen/gntdev: dont ignore kernel unmapping error Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 23/44] xen/gntdev: Prevent leaking grants Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 24/44] mm,hugetlb: take hugetlb_lock before decrementing h->resv_huge_pages Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 25/44] net: ieee802154: fix error return code in dgram_bind() Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 26/44] drm/msm: Fix return type of mdp4_lvds_connector_mode_valid Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 27/44] arc: iounmap() arg is volatile Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 28/44] ALSA: ac97: fix possible memory leak in snd_ac97_dev_register() Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 29/44] kcm: annotate data-races around kcm->rx_psock Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 30/44] kcm: annotate data-races around kcm->rx_wait Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 31/44] net: lantiq_etop: dont free skb when returning NETDEV_TX_BUSY Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 32/44] tcp: fix indefinite deferral of RTO with SACK reneging Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 33/44] can: mscan: mpc5xxx: mpc5xxx_can_probe(): add missing put_clock() in error path Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 34/44] media: vivid: s_fbuf: add more sanity checks Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 35/44] media: vivid: dev->bitmap_cap wasnt freed in all cases Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 36/44] media: v4l2-dv-timings: add sanity checks for blanking values Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 37/44] media: videodev2.h: V4L2_DV_BT_BLANKING_HEIGHT should check interlaced Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 38/44] i40e: Fix ethtool rx-flow-hash setting for X722 Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 39/44] net: ksz884x: fix missing pci_disable_device() on error in pcidev_init() Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 40/44] ALSA: aoa: i2sbus: fix possible memory leak in i2sbus_add_dev() Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 41/44] ALSA: aoa: Fix I2S device accounting Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 42/44] openvswitch: switch from WARN to pr_warn Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 43/44] net: ehea: fix possible memory leak in ehea_register_port() Greg Kroah-Hartman
2022-11-02 2:35 ` [PATCH 4.9 44/44] can: rcar_canfd: rcar_canfd_handle_global_receive(): fix IRQ storm on global FIFO receive Greg Kroah-Hartman
2022-11-02 17:21 ` [PATCH 4.9 00/44] 4.9.332-rc1 review Pavel Machek
2022-11-02 17:32 ` Florian Fainelli
2022-11-02 20:44 ` Guenter Roeck
2022-11-03 11:59 ` Naresh Kamboju
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