| From | Jiri Slaby <> | Subject | [PATCH 3.12 44/72] arc: don't leak bits of kernel stack into coredump | Date | Mon, 7 Nov 2016 14:04:51 +0100 |
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From: Al Viro <viro@zeniv.linux.org.uk>
3.12-stable review patch. If anyone has any objections, please let me know.
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commit 7798bf2140ebcc36eafec6a4194fffd8d585d471 upstream.
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...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jiri Slaby <jslaby@suse.cz> --- arch/arc/kernel/signal.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/arc/kernel/signal.c b/arch/arc/kernel/signal.c index a0c63fc48457..ca6bcd132a14 100644 --- a/arch/arc/kernel/signal.c +++ b/arch/arc/kernel/signal.c @@ -80,13 +80,14 @@ static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf) int err; err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set)); - if (!err) - set_current_blocked(&set); - err |= __copy_from_user(regs, &(sf->uc.uc_mcontext.regs.scratch), sizeof(sf->uc.uc_mcontext.regs.scratch)); + if (err) + return err; - return err; + set_current_blocked(&set); + + return 0; } static inline int is_do_ss_needed(unsigned int magic) -- 2.10.2
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