[PATCH v2 0/2] Fix crash in cper_estatus_check()

From: Ross Lagerwall
Date: Mon Jan 28 2019 - 05:04:36 EST


v2 changes:
- Address Boris's comments.

---

I recently encountered a crash in cper_estatus_check() when called by
bert_init(). Patches follow to fix the problem. Note that I cannot fully
test the patches since the hardware error record on that machine has
been cleared.

The crash log:

[ 125.666350] BUG: unable to handle kernel paging request at ffffc9004046d02c
[ 125.666503] PGD 1f6dce067 P4D 1f6dce067 PUD 1e6532067 PMD 1e3d11067 PTE 0
[ 125.666696] Oops: 0000 [#1] SMP KASAN NOPTI
[ 125.666837] CPU: 7 PID: 1 Comm: swapper/0 Not tainted 4.19.0+0 #1
[ 125.666983] Hardware name: Dell Inc. PowerEdge M520/0DW6GX, BIOS 1.8.6 08/30/2013
[ 125.667171] RIP: e030:cper_estatus_check+0x7e/0xf0
[ 125.667315] Code: 41 29 c5 48 98 48 01 c3 48 89 d8 4c 29 e0 48 39 e8 7d 4a 48 8d 7b 18 be 04 00 00 00 e8 bb 6f 9f ff 48 8d 7b 14 be 02 00 00 00 <44> 8b 73 18 e8 a9 6f 9f ff 0f b6 4b 15 44 89 ee 66 83 f9 03 19 d2
[ 125.667554] RSP: e02b:ffff8881e65efce0 EFLAGS: 00010246
[ 125.667699] RAX: fffff5200808da06 RBX: ffffc9004046d014 RCX: ffffffff8192bf25
[ 125.667849] RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffffc9004046d028
[ 125.668009] RBP: 0000000000000700 R08: fffff5200808da06 R09: fffff5200808da06
[ 125.668207] R10: 0000000000000001 R11: fffff5200808da05 R12: ffffc9004046cc14
[ 125.668358] R13: 0000000000000300 R14: 00000000000000c0 R15: ffffc9004046cc00
[ 125.668519] FS: 0000000000000000(0000) GS:ffff8881e77c0000(0000) knlGS:0000000000000000
[ 125.668698] CS: e033 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 125.668844] CR2: ffffc9004046d02c CR3: 000000000260c000 CR4: 0000000000042660
[ 125.668999] Call Trace:
[ 125.669139] bert_init+0x21c/0x362
[ 125.669279] ? setup_bert_disable+0x12/0x12
[ 125.669420] ? pci_get_dev_by_id+0x57/0x70
[ 125.669560] ? pci_get_device+0x86/0xc0
[ 125.669738] ? pci_create_sysfs_dev_files+0x1a6/0x330
[ 125.669883] ? setup_bert_disable+0x12/0x12
[ 125.670026] ? set_debug_rodata+0x11/0x11
[ 125.670166] ? do_one_initcall+0x8b/0x253
[ 125.670306] do_one_initcall+0x8b/0x253
[ 125.670447] ? perf_trace_initcall_level+0x250/0x250
[ 125.670592] ? __wake_up_common+0x140/0x1d0
[ 125.670736] ? kasan_unpoison_shadow+0x30/0x40
[ 125.670879] ? kasan_unpoison_shadow+0x30/0x40
[ 125.671023] ? set_debug_rodata+0x11/0x11
[ 125.671164] kernel_init_freeable+0x269/0x304
[ 125.671346] ? rest_init+0xc0/0xc0
[ 125.671485] kernel_init+0xf/0x130
[ 125.671623] ? rest_init+0xc0/0xc0
[ 125.671761] ? rest_init+0xc0/0xc0
[ 125.671901] ret_from_fork+0x35/0x40
[ 125.672063] Modules linked in:
[ 125.672201] CR2: ffffc9004046d02c
[ 125.672349] ---[ end trace a17cd87742b2c49e ]---
[ 125.683693] RIP: e030:cper_estatus_check+0x7e/0xf0
[ 125.683840] Code: 41 29 c5 48 98 48 01 c3 48 89 d8 4c 29 e0 48 39 e8 7d 4a 48 8d 7b 18 be 04 00 00 00 e8 bb 6f 9f ff 48 8d 7b 14 be 02 00 00 00 <44> 8b 73 18 e8 a9 6f 9f ff 0f b6 4b 15 44 89 ee 66 83 f9 03 19 d2
[ 125.684103] RSP: e02b:ffff8881e65efce0 EFLAGS: 00010246
[ 125.684247] RAX: fffff5200808da06 RBX: ffffc9004046d014 RCX: ffffffff8192bf25
[ 125.684397] RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffffc9004046d028
[ 125.684548] RBP: 0000000000000700 R08: fffff5200808da06 R09: fffff5200808da06
[ 125.684699] R10: 0000000000000001 R11: fffff5200808da05 R12: ffffc9004046cc14
[ 125.684850] R13: 0000000000000300 R14: 00000000000000c0 R15: ffffc9004046cc00
[ 125.685009] FS: 0000000000000000(0000) GS:ffff8881e77c0000(0000) knlGS:0000000000000000
[ 125.685224] CS: e033 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 125.685371] CR2: ffffc9004046d02c CR3: 000000000260c000 CR4: 0000000000042660
[ 125.685566] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009

Thanks,

Ross Lagerwall (2):
acpi/apei: Fix possible out-of-bounds access to BERT region
efi/cper: Fix possible out-of-bounds access

drivers/acpi/apei/bert.c | 23 ++++++++++-------------
drivers/firmware/efi/cper.c | 13 +++++++++----
2 files changed, 19 insertions(+), 17 deletions(-)

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2.17.2