Coly Li
374eec8218
bcache: fix memory corruption in bch_cache_accounting_clear()
...
[ Upstream commit 5bebf7486d4f4940b2a8e4009beb1dff5041853d ]
Commit 83ff9318c4 ("bcache: not use hard coded memset size in
bch_cache_accounting_clear()") tries to make the code more easy to
understand by removing the hard coded number with following change,
void bch_cache_accounting_clear(...)
{
memset(&acc->total.cache_hits,
0,
- sizeof(unsigned long) * 7);
+ sizeof(struct cache_stats));
}
Unfortunately the change was wrong (it also tells us the original code
was not easy to correctly understand). The hard coded number 7 is used
because in struct cache_stats,
15 struct cache_stats {
16 struct kobject kobj;
17
18 unsigned long cache_hits;
19 unsigned long cache_misses;
20 unsigned long cache_bypass_hits;
21 unsigned long cache_bypass_misses;
22 unsigned long cache_readaheads;
23 unsigned long cache_miss_collisions;
24 unsigned long sectors_bypassed;
25
26 unsigned int rescale;
27 };
only members in LINE 18-24 want to be set to 0. It is wrong to use
'sizeof(struct cache_stats)' to replace 'sizeof(unsigned long) * 7), the
memory objects behind acc->total is staled by this change.
Сорокин Артем Сергеевич reports that by the following steps, kernel
panic will be triggered,
1. Create new set: make-bcache -B /dev/nvme1n1 -C /dev/sda --wipe-bcache
2. Run in /sys/fs/bcache/<uuid>:
echo 1 > clear_stats && cat stats_five_minute/cache_bypass_hits
I can reproduce the panic and get following dmesg with KASAN enabled,
[22613.172742] ==================================================================
[22613.172862] BUG: KASAN: null-ptr-deref in sysfs_kf_seq_show+0x117/0x230
[22613.172864] Read of size 8 at addr 0000000000000000 by task cat/6753
[22613.172870] CPU: 1 PID: 6753 Comm: cat Not tainted 5.5.0-rc7-lp151.28.16-default+ #11
[22613.172872] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/29/2019
[22613.172873] Call Trace:
[22613.172964] dump_stack+0x8b/0xbb
[22613.172968] ? sysfs_kf_seq_show+0x117/0x230
[22613.172970] ? sysfs_kf_seq_show+0x117/0x230
[22613.173031] __kasan_report+0x176/0x192
[22613.173064] ? pr_cont_kernfs_name+0x40/0x60
[22613.173067] ? sysfs_kf_seq_show+0x117/0x230
[22613.173070] kasan_report+0xe/0x20
[22613.173072] sysfs_kf_seq_show+0x117/0x230
[22613.173105] seq_read+0x199/0x6d0
[22613.173110] vfs_read+0xa5/0x1a0
[22613.173113] ksys_read+0x110/0x160
[22613.173115] ? kernel_write+0xb0/0xb0
[22613.173177] do_syscall_64+0x77/0x290
[22613.173238] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[22613.173241] RIP: 0033:0x7fc2c886ac61
[22613.173244] Code: fe ff ff 48 8d 3d c7 a0 09 00 48 83 ec 08 e8 46 03 02 00 66 0f 1f 44 00 00 8b 05 ca fb 2c 00 48 63 ff 85 c0 75 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 57 f3 c3 0f 1f 44 00 00 55 53 48 89 d5 48 89
[22613.173245] RSP: 002b:00007ffebe776d68 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[22613.173248] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007fc2c886ac61
[22613.173249] RDX: 0000000000020000 RSI: 00007fc2c8cca000 RDI: 0000000000000003
[22613.173250] RBP: 0000000000020000 R08: ffffffffffffffff R09: 0000000000000000
[22613.173251] R10: 000000000000038c R11: 0000000000000246 R12: 00007fc2c8cca000
[22613.173253] R13: 0000000000000003 R14: 00007fc2c8cca00f R15: 0000000000020000
[22613.173255] ==================================================================
[22613.173256] Disabling lock debugging due to kernel taint
[22613.173350] BUG: kernel NULL pointer dereference, address: 0000000000000000
[22613.178380] #PF: supervisor read access in kernel mode
[22613.180959] #PF: error_code(0x0000) - not-present page
[22613.183444] PGD 0 P4D 0
[22613.184867] Oops: 0000 [#1 ] SMP KASAN PTI
[22613.186797] CPU: 1 PID: 6753 Comm: cat Tainted: G B 5.5.0-rc7-lp151.28.16-default+ #11
[22613.191253] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/29/2019
[22613.196706] RIP: 0010:sysfs_kf_seq_show+0x117/0x230
[22613.199097] Code: ff 48 8b 0b 48 8b 44 24 08 48 01 e9 eb a6 31 f6 48 89 cf ba 00 10 00 00 48 89 4c 24 10 e8 b1 e6 e9 ff 4c 89 ff e8 19 07 ea ff <49> 8b 07 48 85 c0 48 89 44 24 08 0f 84 91 00 00 00 49 8b 6d 00 48
[22613.208016] RSP: 0018:ffff8881d4f8fd78 EFLAGS: 00010246
[22613.210448] RAX: 0000000000000000 RBX: ffff8881eb99b180 RCX: ffffffff810d9ef6
[22613.213691] RDX: 0000000000000001 RSI: 0000000000000246 RDI: 0000000000000246
[22613.216893] RBP: 0000000000001000 R08: fffffbfff072ddcd R09: fffffbfff072ddcd
[22613.220075] R10: 0000000000000001 R11: fffffbfff072ddcc R12: ffff8881de5c0200
[22613.223256] R13: ffff8881ed175500 R14: ffff8881eb99b198 R15: 0000000000000000
[22613.226290] FS: 00007fc2c8d3d500(0000) GS:ffff8881f2a80000(0000) knlGS:0000000000000000
[22613.229637] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[22613.231993] CR2: 0000000000000000 CR3: 00000001ec89a004 CR4: 00000000003606e0
[22613.234909] Call Trace:
[22613.235931] seq_read+0x199/0x6d0
[22613.237259] vfs_read+0xa5/0x1a0
[22613.239229] ksys_read+0x110/0x160
[22613.240590] ? kernel_write+0xb0/0xb0
[22613.242040] do_syscall_64+0x77/0x290
[22613.243625] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[22613.245450] RIP: 0033:0x7fc2c886ac61
[22613.246706] Code: fe ff ff 48 8d 3d c7 a0 09 00 48 83 ec 08 e8 46 03 02 00 66 0f 1f 44 00 00 8b 05 ca fb 2c 00 48 63 ff 85 c0 75 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 57 f3 c3 0f 1f 44 00 00 55 53 48 89 d5 48 89
[22613.253296] RSP: 002b:00007ffebe776d68 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[22613.255835] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007fc2c886ac61
[22613.258472] RDX: 0000000000020000 RSI: 00007fc2c8cca000 RDI: 0000000000000003
[22613.260807] RBP: 0000000000020000 R08: ffffffffffffffff R09: 0000000000000000
[22613.263188] R10: 000000000000038c R11: 0000000000000246 R12: 00007fc2c8cca000
[22613.265598] R13: 0000000000000003 R14: 00007fc2c8cca00f R15: 0000000000020000
[22613.268729] Modules linked in: scsi_transport_iscsi af_packet iscsi_ibft iscsi_boot_sysfs vmw_vsock_vmci_transport vsock fuse bnep kvm_intel kvm irqbypass crc32_pclmul crc32c_intel ghash_clmulni_intel snd_ens1371 snd_ac97_codec ac97_bus bcache snd_pcm btusb btrtl btbcm btintel crc64 aesni_intel glue_helper crypto_simd vmw_balloon cryptd bluetooth snd_timer snd_rawmidi snd joydev pcspkr e1000 rfkill vmw_vmci soundcore ecdh_generic ecc gameport i2c_piix4 mptctl ac button hid_generic usbhid sr_mod cdrom ata_generic ehci_pci vmwgfx uhci_hcd drm_kms_helper syscopyarea serio_raw sysfillrect sysimgblt fb_sys_fops ttm ehci_hcd mptspi scsi_transport_spi mptscsih ata_piix mptbase ahci usbcore libahci drm sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua
[22613.292429] CR2: 0000000000000000
[22613.293563] ---[ end trace a074b26a8508f378 ]---
[22613.295138] RIP: 0010:sysfs_kf_seq_show+0x117/0x230
[22613.296769] Code: ff 48 8b 0b 48 8b 44 24 08 48 01 e9 eb a6 31 f6 48 89 cf ba 00 10 00 00 48 89 4c 24 10 e8 b1 e6 e9 ff 4c 89 ff e8 19 07 ea ff <49> 8b 07 48 85 c0 48 89 44 24 08 0f 84 91 00 00 00 49 8b 6d 00 48
[22613.303553] RSP: 0018:ffff8881d4f8fd78 EFLAGS: 00010246
[22613.305280] RAX: 0000000000000000 RBX: ffff8881eb99b180 RCX: ffffffff810d9ef6
[22613.307924] RDX: 0000000000000001 RSI: 0000000000000246 RDI: 0000000000000246
[22613.310272] RBP: 0000000000001000 R08: fffffbfff072ddcd R09: fffffbfff072ddcd
[22613.312685] R10: 0000000000000001 R11: fffffbfff072ddcc R12: ffff8881de5c0200
[22613.315076] R13: ffff8881ed175500 R14: ffff8881eb99b198 R15: 0000000000000000
[22613.318116] FS: 00007fc2c8d3d500(0000) GS:ffff8881f2a80000(0000) knlGS:0000000000000000
[22613.320743] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[22613.322628] CR2: 0000000000000000 CR3: 00000001ec89a004 CR4: 00000000003606e0
Here this patch fixes the following problem by explicity set all the 7
members to 0 in bch_cache_accounting_clear().
Reported-by: Сорокин Артем Сергеевич <a.sorokin@bank-hlynov.ru>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-24 08:37:01 +01:00
arch
powerpc: Do not consider weak unresolved symbol relocations as bad
2020-02-24 08:37:00 +01:00
block
block, bfq: do not plug I/O for bfq_queues with no proc refs
2020-02-24 08:36:31 +01:00
certs
crypto
crypto: essiv - fix AEAD capitalization and preposition use in help text
2020-02-24 08:36:50 +01:00
Documentation
fbdev: fix numbering of fbcon options
2020-02-24 08:36:42 +01:00
drivers
bcache: fix memory corruption in bch_cache_accounting_clear()
2020-02-24 08:37:01 +01:00
fs
reiserfs: prevent NULL pointer dereference in reiserfs_insert_item()
2020-02-24 08:37:00 +01:00
include
raid6/test: fix a compilation warning
2020-02-24 08:36:47 +01:00
init
Revert "um: Enable CONFIG_CONSTRUCTORS"
2020-02-01 09:34:53 +00:00
ipc
ipc/msg.c: consolidate all xxxctl_down() functions
2020-02-11 04:35:07 -08:00
kernel
trigger_next should increase position index
2020-02-24 08:36:59 +01:00
lib
lib/scatterlist.c: adjust indentation in __sg_alloc_table
2020-02-24 08:37:00 +01:00
LICENSES
mm
mm/mmu_gather: invalidate TLB correctly on batch allocation failure and flush
2020-02-11 04:35:42 -08:00
net
sunrpc: Fix potential leaks in sunrpc_cache_unhash()
2020-02-24 08:36:55 +01:00
samples
samples/bpf: Set -fno-stack-protector when building BPF programs
2020-02-24 08:36:36 +01:00
scripts
bpf, btf: Always output invariant hit in pahole DWARF to BTF transform
2020-02-24 08:36:55 +01:00
security
selinux: ensure we cleanup the internal AVC counters on error in avc_update()
2020-02-24 08:36:39 +01:00
sound
ALSA: usb-audio: add quirks for Line6 Helix devices fw>=2.82
2020-02-24 08:36:58 +01:00
tools
selftests/eeh: Bump EEH wait time to 60s
2020-02-24 08:36:57 +01:00
usr
gen_initramfs_list.sh: fix 'bad variable name' error
2020-01-09 10:20:00 +01:00
virt
KVM: arm64: Treat emulated TVAL TimerValue as a signed 32-bit integer
2020-02-14 16:34:18 -05:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
ARM: SoC fixes
2019-11-10 13:41:59 -08:00
COPYING
CREDITS
MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer
2019-10-10 08:12:51 -07:00
Kbuild
Kconfig
MAINTAINERS
MAINTAINERS: correct entries for ISDN/mISDN section
2020-02-11 04:35:06 -08:00
Makefile
Linux 5.4.21
2020-02-19 19:53:10 +01:00
README