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| author | Mark Rutland <mark.rutland@arm.com> | 2018-04-25 17:13:40 +0100 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2018-04-26 16:58:39 +0100 |
| commit | 19791a7ca674fb3009bb068260e852a2f05b605c (patch) | |
| tree | dd3b7b1e9dc98708b0f28711df83b16b7eb85ebf | |
| parent | ad40bdafb495f30e5af837e15b3c2a4cb2176e47 (diff) | |
| download | linux-stable-19791a7ca674fb3009bb068260e852a2f05b605c.tar.gz linux-stable-19791a7ca674fb3009bb068260e852a2f05b605c.tar.bz2 linux-stable-19791a7ca674fb3009bb068260e852a2f05b605c.zip | |
arm64: fix possible spectre-v1 in ptrace_hbp_get_event()
It's possible for userspace to control idx. Sanitize idx when using it
as an array index.
Found by smatch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
| -rw-r--r-- | arch/arm64/kernel/ptrace.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 7a832ce6552f..7ff81fed46e1 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -25,6 +25,7 @@ #include <linux/sched/signal.h> #include <linux/sched/task_stack.h> #include <linux/mm.h> +#include <linux/nospec.h> #include <linux/smp.h> #include <linux/ptrace.h> #include <linux/user.h> @@ -249,15 +250,20 @@ static struct perf_event *ptrace_hbp_get_event(unsigned int note_type, switch (note_type) { case NT_ARM_HW_BREAK: - if (idx < ARM_MAX_BRP) - bp = tsk->thread.debug.hbp_break[idx]; + if (idx >= ARM_MAX_BRP) + goto out; + idx = array_index_nospec(idx, ARM_MAX_BRP); + bp = tsk->thread.debug.hbp_break[idx]; break; case NT_ARM_HW_WATCH: - if (idx < ARM_MAX_WRP) - bp = tsk->thread.debug.hbp_watch[idx]; + if (idx >= ARM_MAX_WRP) + goto out; + idx = array_index_nospec(idx, ARM_MAX_WRP); + bp = tsk->thread.debug.hbp_watch[idx]; break; } +out: return bp; } |