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authorDave Martin <Dave.Martin@arm.com>2017-03-27 15:10:54 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-03-31 09:49:53 +0200
commite1dc8904b33b8c01f22d904fed4cb5f2060f5da3 (patch)
tree59110962d9aaab7674d09855919cd3d01227423b
parent6e174bbd0631865acc193804fa4043852f3198c5 (diff)
h8300/ptrace: Fix incorrect register transfer count
commit 502585c7555083d4a949c08350306b9ec196779e upstream. regs_set() and regs_get() are vulnerable to an off-by-1 buffer overrun if CONFIG_CPU_H8S is set, since this adds an extra entry to register_offset[] but not to user_regs_struct. So, iterate over user_regs_struct based on its actual size, not based on the length of register_offset[]. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/h8300/kernel/ptrace.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/arch/h8300/kernel/ptrace.c b/arch/h8300/kernel/ptrace.c
index 92075544a19a..0dc1c8f622bc 100644
--- a/arch/h8300/kernel/ptrace.c
+++ b/arch/h8300/kernel/ptrace.c
@@ -95,7 +95,8 @@ static int regs_get(struct task_struct *target,
long *reg = (long *)&regs;
/* build user regs in buffer */
- for (r = 0; r < ARRAY_SIZE(register_offset); r++)
+ BUILD_BUG_ON(sizeof(regs) % sizeof(long) != 0);
+ for (r = 0; r < sizeof(regs) / sizeof(long); r++)
*reg++ = h8300_get_reg(target, r);
return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
@@ -113,7 +114,8 @@ static int regs_set(struct task_struct *target,
long *reg;
/* build user regs in buffer */
- for (reg = (long *)&regs, r = 0; r < ARRAY_SIZE(register_offset); r++)
+ BUILD_BUG_ON(sizeof(regs) % sizeof(long) != 0);
+ for (reg = (long *)&regs, r = 0; r < sizeof(regs) / sizeof(long); r++)
*reg++ = h8300_get_reg(target, r);
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
@@ -122,7 +124,7 @@ static int regs_set(struct task_struct *target,
return ret;
/* write back to pt_regs */
- for (reg = (long *)&regs, r = 0; r < ARRAY_SIZE(register_offset); r++)
+ for (reg = (long *)&regs, r = 0; r < sizeof(regs) / sizeof(long); r++)
h8300_put_reg(target, r, *reg++);
return 0;
}