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authorStephen Boyd <sboyd@codeaurora.org>2013-08-08 18:41:59 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2013-08-13 20:21:44 +0100
commitd9f966357b14e356dbd83b8f4a197a287ab4ff83 (patch)
treee99891f5616cc8e33d592ab15822e0fc7bba7ca1 /arch/arm/kernel/perf_event.c
parentc95eb3184ea1a3a2551df57190c81da695e2144b (diff)
downloadlinux-d9f966357b14e356dbd83b8f4a197a287ab4ff83.tar.gz
ARM: 7810/1: perf: Fix array out of bounds access in armpmu_map_hw_event()
Vince Weaver reports an oops in the ARM perf event code while running his perf_fuzzer tool on a pandaboard running v3.11-rc4. Unable to handle kernel paging request at virtual address 73fd14cc pgd = eca6c000 [73fd14cc] *pgd=00000000 Internal error: Oops: 5 [#1] SMP ARM Modules linked in: snd_soc_omap_hdmi omapdss snd_soc_omap_abe_twl6040 snd_soc_twl6040 snd_soc_omap snd_soc_omap_hdmi_card snd_soc_omap_mcpdm snd_soc_omap_mcbsp snd_soc_core snd_compress regmap_spi snd_pcm snd_page_alloc snd_timer snd soundcore CPU: 1 PID: 2790 Comm: perf_fuzzer Not tainted 3.11.0-rc4 #6 task: eddcab80 ti: ed892000 task.ti: ed892000 PC is at armpmu_map_event+0x20/0x88 LR is at armpmu_event_init+0x38/0x280 pc : [<c001c3e4>] lr : [<c001c17c>] psr: 60000013 sp : ed893e40 ip : ecececec fp : edfaec00 r10: 00000000 r9 : 00000000 r8 : ed8c3ac0 r7 : ed8c3b5c r6 : edfaec00 r5 : 00000000 r4 : 00000000 r3 : 000000ff r2 : c0496144 r1 : c049611c r0 : edfaec00 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 10c5387d Table: aca6c04a DAC: 00000015 Process perf_fuzzer (pid: 2790, stack limit = 0xed892240) Stack: (0xed893e40 to 0xed894000) 3e40: 00000800 c001c17c 00000002 c008a748 00000001 00000000 00000000 c00bf078 3e60: 00000000 edfaee50 00000000 00000000 00000000 edfaec00 ed8c3ac0 edfaec00 3e80: 00000000 c073ffac ed893f20 c00bf180 00000001 00000000 c00bf078 ed893f20 3ea0: 00000000 ed8c3ac0 00000000 00000000 00000000 c0cb0818 eddcab80 c00bf440 3ec0: ed893f20 00000000 eddcab80 eca76800 00000000 eca76800 00000000 00000000 3ee0: 00000000 ec984c80 eddcab80 c00bfe68 00000000 00000000 00000000 00000080 3f00: 00000000 ed892000 00000000 ed892030 00000004 ecc7e3c8 ecc7e3c8 00000000 3f20: 00000000 00000048 ecececec 00000000 00000000 00000000 00000000 00000000 3f40: 00000000 00000000 00297810 00000000 00000000 00000000 00000000 00000000 3f60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 3f80: 00000002 00000002 000103a4 00000002 0000016c c00128e8 ed892000 00000000 3fa0: 00090998 c0012700 00000002 000103a4 00090ab8 00000000 00000000 0000000f 3fc0: 00000002 000103a4 00000002 0000016c 00090ab0 00090ab8 000107a0 00090998 3fe0: bed92be0 bed92bd0 0000b785 b6e8f6d0 40000010 00090ab8 00000000 00000000 [<c001c3e4>] (armpmu_map_event+0x20/0x88) from [<c001c17c>] (armpmu_event_init+0x38/0x280) [<c001c17c>] (armpmu_event_init+0x38/0x280) from [<c00bf180>] (perf_init_event+0x108/0x180) [<c00bf180>] (perf_init_event+0x108/0x180) from [<c00bf440>] (perf_event_alloc+0x248/0x40c) [<c00bf440>] (perf_event_alloc+0x248/0x40c) from [<c00bfe68>] (SyS_perf_event_open+0x4f4/0x8fc) [<c00bfe68>] (SyS_perf_event_open+0x4f4/0x8fc) from [<c0012700>] (ret_fast_syscall+0x0/0x48) Code: 0a000005 e3540004 0a000016 e3540000 (0791010c) This is because event->attr.config in armpmu_event_init() contains a very large number copied directly from userspace and is never checked against the size of the array indexed in armpmu_map_hw_event(). Fix the problem by checking the value of config before indexing the array and rejecting invalid config values. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Tested-by: Vince Weaver <vincent.weaver@maine.edu> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/perf_event.c')
-rw-r--r--arch/arm/kernel/perf_event.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 0500f10b5041..e186ee1e63f6 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -53,7 +53,12 @@ armpmu_map_cache_event(const unsigned (*cache_map)
static int
armpmu_map_hw_event(const unsigned (*event_map)[PERF_COUNT_HW_MAX], u64 config)
{
- int mapping = (*event_map)[config];
+ int mapping;
+
+ if (config >= PERF_COUNT_HW_MAX)
+ return -EINVAL;
+
+ mapping = (*event_map)[config];
return mapping == HW_OP_UNSUPPORTED ? -ENOENT : mapping;
}