diff options
| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-07-30 13:04:49 +0200 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2014-07-30 18:02:45 +0200 |
| commit | cbcbb4c4826ff594b091e143b0f049f13ab7a64e (patch) | |
| tree | 840610372fbdfbae6e95c385a7d44060f5c94de8 | |
| parent | d83a3234d2e1e2a55e7f2430fc9ca29a9bd315e7 (diff) | |
s390/ptrace: fix PSW mask check
commit dab6cf55f81a6e16b8147aed9a843e1691dcd318 upstream.
The PSW mask check of the PTRACE_POKEUSR_AREA command is incorrect.
The PSW_MASK_USER define contains the PSW_MASK_ASC bits, the ptrace
interface accepts all combinations for the address-space-control
bits. To protect the kernel space the PSW mask check in ptrace needs
to reject the address-space-control bit combination for home space.
Fixes CVE-2014-3534
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| -rw-r--r-- | arch/s390/kernel/ptrace.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c index 9556905bd3ce..d4c5e6ba8410 100644 --- a/arch/s390/kernel/ptrace.c +++ b/arch/s390/kernel/ptrace.c @@ -322,7 +322,9 @@ static int __poke_user(struct task_struct *child, addr_t addr, addr_t data) * psw and gprs are stored on the stack */ if (addr == (addr_t) &dummy->regs.psw.mask && - ((data & ~PSW_MASK_USER) != psw_user_bits || + (((data^psw_user_bits) & ~PSW_MASK_USER) || + (((data^psw_user_bits) & PSW_MASK_ASC) && + ((data|psw_user_bits) & PSW_MASK_ASC) == PSW_MASK_ASC) || ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA)))) /* Invalid psw mask. */ return -EINVAL; @@ -655,7 +657,10 @@ static int __poke_user_compat(struct task_struct *child, */ if (addr == (addr_t) &dummy32->regs.psw.mask) { /* Build a 64 bit psw mask from 31 bit mask. */ - if ((tmp & ~PSW32_MASK_USER) != psw32_user_bits) + if (((tmp^psw32_user_bits) & ~PSW32_MASK_USER) || + (((tmp^psw32_user_bits) & PSW32_MASK_ASC) && + ((tmp|psw32_user_bits) & PSW32_MASK_ASC) + == PSW32_MASK_ASC)) /* Invalid psw mask. */ return -EINVAL; regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) | |