Commit 7798bf21 authored by Al Viro's avatar Al Viro

arc: don't leak bits of kernel stack into coredump

On faulting sigreturn we do get SIGSEGV, all right, but anything
we'd put into pt_regs could end up in the coredump.  And since
__copy_from_user() never zeroed on arc, we'd better bugger off
on its failure without copying random uninitialized bits of
kernel stack into pt_regs...

Cc: stable@vger.kernel.org
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 085354f9
...@@ -107,13 +107,13 @@ static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf) ...@@ -107,13 +107,13 @@ static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf)
struct user_regs_struct uregs; struct user_regs_struct uregs;
err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set)); err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
if (!err)
set_current_blocked(&set);
err |= __copy_from_user(&uregs.scratch, err |= __copy_from_user(&uregs.scratch,
&(sf->uc.uc_mcontext.regs.scratch), &(sf->uc.uc_mcontext.regs.scratch),
sizeof(sf->uc.uc_mcontext.regs.scratch)); sizeof(sf->uc.uc_mcontext.regs.scratch));
if (err)
return err;
set_current_blocked(&set);
regs->bta = uregs.scratch.bta; regs->bta = uregs.scratch.bta;
regs->lp_start = uregs.scratch.lp_start; regs->lp_start = uregs.scratch.lp_start;
regs->lp_end = uregs.scratch.lp_end; regs->lp_end = uregs.scratch.lp_end;
...@@ -138,7 +138,7 @@ static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf) ...@@ -138,7 +138,7 @@ static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf)
regs->r0 = uregs.scratch.r0; regs->r0 = uregs.scratch.r0;
regs->sp = uregs.scratch.sp; regs->sp = uregs.scratch.sp;
return err; return 0;
} }
static inline int is_do_ss_needed(unsigned int magic) static inline int is_do_ss_needed(unsigned int magic)
......
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