diff options
| author | Paul Mackerras <paulus@samba.org> | 2006-06-09 13:02:59 +1000 |
|---|---|---|
| committer | Paul Mackerras <paulus@samba.org> | 2006-06-09 13:02:59 +1000 |
| commit | 7c85d1f9d358b24c5b05c3a2783a78423775a080 (patch) | |
| tree | 71f92966cba279120cb81965cb3a5294295413ba /arch/powerpc/kernel/signal_32.c | |
| parent | 1def630a6a49dda5bc89dfbd86656293640456f0 (diff) | |
powerpc: Fix machine check problem on 32-bit kernels
This fixes a bug found by Dave Jones that means that it is possible
for userspace to provoke a machine check on 32-bit kernels. This
also fixes a couple of other places where I found similar problems
by inspection.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/kernel/signal_32.c')
| -rw-r--r-- | arch/powerpc/kernel/signal_32.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index 01e3c08cb550..8fdeca2d4597 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -803,10 +803,13 @@ static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int if (__get_user(cmcp, &ucp->uc_regs)) return -EFAULT; mcp = (struct mcontext __user *)(u64)cmcp; + /* no need to check access_ok(mcp), since mcp < 4GB */ } #else if (__get_user(mcp, &ucp->uc_regs)) return -EFAULT; + if (!access_ok(VERIFY_READ, mcp, sizeof(*mcp))) + return -EFAULT; #endif restore_sigmask(&set); if (restore_user_regs(regs, mcp, sig)) @@ -908,13 +911,14 @@ int sys_debug_setcontext(struct ucontext __user *ctx, { struct sig_dbg_op op; int i; + unsigned char tmp; unsigned long new_msr = regs->msr; #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) unsigned long new_dbcr0 = current->thread.dbcr0; #endif for (i=0; i<ndbg; i++) { - if (__copy_from_user(&op, dbg, sizeof(op))) + if (copy_from_user(&op, dbg + i, sizeof(op))) return -EFAULT; switch (op.dbg_type) { case SIG_DBG_SINGLE_STEPPING: @@ -959,6 +963,11 @@ int sys_debug_setcontext(struct ucontext __user *ctx, current->thread.dbcr0 = new_dbcr0; #endif + if (!access_ok(VERIFY_READ, ctx, sizeof(*ctx)) + || __get_user(tmp, (u8 __user *) ctx) + || __get_user(tmp, (u8 __user *) (ctx + 1) - 1)) + return -EFAULT; + /* * If we get a fault copying the context into the kernel's * image of the user's registers, we can't just return -EFAULT |