3.16.42-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Dave Martin <[email protected]> commit ad9e202aa1ce571b1d7fed969d06f66067f8a086 upstream. We cannot preserve partial fields for hardware breakpoints, because the values written by userspace to the hardware breakpoint registers can't subsequently be recovered intact from the hardware. So, just reject attempts to write incomplete fields with -EINVAL. Fixes: 478fcb2cdb23 ("arm64: Debugging support") Signed-off-by: Dave Martin <[email protected]> Acked-by: Will Deacon <[email protected]> Signed-off-by: Catalin Marinas <[email protected]> Signed-off-by: Ben Hutchings <[email protected]> --- arch/arm64/kernel/ptrace.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -446,6 +446,8 @@ static int hw_break_set(struct task_stru /* (address, ctrl) registers */ limit = regset->n * regset->size; while (count && offset < limit) { + if (count < PTRACE_HBP_ADDR_SZ) + return -EINVAL; ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr, offset, offset + PTRACE_HBP_ADDR_SZ); if (ret) @@ -455,6 +457,8 @@ static int hw_break_set(struct task_stru return ret; offset += PTRACE_HBP_ADDR_SZ; + if (!count) + break; ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl, offset, offset + PTRACE_HBP_CTRL_SZ); if (ret)
