dect
/
linux-2.6
Archived
13
0
Fork 0
Code Releases Activity

ARM: 7526/1: traps: send SIGILL if get_user fails on undef handling path 

get_user may fail to load from the provided __user address due to an
unhandled fault generated by the access.

In the case of the undefined instruction trap, this results in failure
to load the faulting instruction, in which case we should send SIGILL to
the task rather than continue with potentially uninitialised data.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Will Deacon 2012-09-07 18:21:44 +01:00 committed by Russell King
parent 62194bdab8
commit 2b2040af0b
1 changed files with 7 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
arch/arm/kernel/traps.c
View File

@ -420,20 +420,23 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
#endif
instr = *(u32 *) pc;
} else if (thumb_mode(regs)) {
get_user(instr, (u16 __user *)pc);
if (get_user(instr, (u16 __user *)pc))
goto die_sig;
if (is_wide_instruction(instr)) {
unsigned int instr2;
get_user(instr2, (u16 __user *)pc+1);
if (get_user(instr2, (u16 __user *)pc+1))
goto die_sig;
instr <<= 16;
instr |= instr2;
}
} else {
get_user(instr, (u32 __user *)pc);
} else if (get_user(instr, (u32 __user *)pc)) {
goto die_sig;
}
if (call_undef_hook(regs, instr) == 0)
return;
die_sig:
#ifdef CONFIG_DEBUG_USER
if (user_debug & UDBG_UNDEFINED) {
printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n",