diff options
| author | Dave Martin <Dave.Martin@arm.com> | 2017-01-18 16:25:24 +0000 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@verizon.com> | 2017-03-06 17:29:28 -0500 |
| commit | 6b6b456e82e052212ae7c9ef06cb78cd36b05362 (patch) | |
| tree | 393d2965c520c5833ddc8b671949ec23d61c672f /arch | |
| parent | 113634c09aa0f3196d8882116d9b2580954644bd (diff) | |
arm64/ptrace: Reject attempts to set incomplete hardware breakpoint fields
[ Upstream commit ad9e202aa1ce571b1d7fed969d06f66067f8a086 ]
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.
Cc: <stable@vger.kernel.org> # 3.7.x-
Fixes: 478fcb2cdb23 ("arm64: Debugging support")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Will Deacon <Will.Deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/kernel/ptrace.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index a9749cdcdb14..f7738bbc8c3f 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -450,6 +450,8 @@ static int hw_break_set(struct task_struct *target, /* (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) @@ -459,6 +461,8 @@ static int hw_break_set(struct task_struct *target, 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) |