3.16.52-rc1 review patch. If anyone has any objections, please let me know.
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From: Mark Rutland mark.rutland@arm.com
commit 7a7003b1da010d2b0d1dc8bf21c10f5c73b389f1 upstream.
It's possible for a user to deliberately trigger __dump_instr with a chosen kernel address.
Let's avoid problems resulting from this by using get_user() rather than __get_user(), ensuring that we don't erroneously access kernel memory.
Where we use __dump_instr() on kernel text, we already switch to KERNEL_DS, so this shouldn't adversely affect those cases.
Fixes: 60ffc30d5652810d ("arm64: Exception handling") Acked-by: Will Deacon will.deacon@arm.com Signed-off-by: Mark Rutland mark.rutland@arm.com Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Ben Hutchings ben@decadent.org.uk --- arch/arm64/kernel/traps.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -105,7 +105,7 @@ static void __dump_instr(const char *lvl for (i = -4; i < 1; i++) { unsigned int val, bad;
- bad = __get_user(val, &((u32 *)addr)[i]); + bad = get_user(val, &((u32 *)addr)[i]);
if (!bad) p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val);