From b140f25108a8b11aa4903014814988549838b324 Mon Sep 17 00:00:00 2001 From: Alexey Kuznetsov Date: Tue, 8 May 2007 00:31:57 -0700 Subject: [PATCH] Invalid return value of execve() resulting in oopses When elf loader fails to map executable (due to memory shortage or because binary is malformed), it can return 0. Normally, this is invisible because process is killed with SIGKILL and it never returns to user space. But if exec() is called from kernel thread (hotplug, whatever) consequences are more interesting and vary depending on architecture. i386. Nothing especially interesting, execve() just returns with "success" :-) x86_64. Fake zero frame is used on way to caller, RSP/RIP are loaded with zeros, ergo... double fault. ia64. Similar to i386, but r32...r95 are corrupted. Sometimes it oopses due to return to zero PC, sometimes it sees NaT in rXX and oopses due to NaT consumption. Signed-off-by: Alexey Kuznetsov Signed-off-by: Kirill Korotaev Signed-off-by: Pavel Emelianov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/binfmt_elf.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 67d9b3148c0..fa8ea33ab0b 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -871,6 +871,8 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs) elf_prot, elf_flags); if (BAD_ADDR(error)) { send_sig(SIGKILL, current, 0); + retval = IS_ERR((void *)error) ? + PTR_ERR((void*)error) : -EINVAL; goto out_free_dentry; } @@ -900,6 +902,7 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs) TASK_SIZE - elf_ppnt->p_memsz < k) { /* set_brk can never work. Avoid overflows. */ send_sig(SIGKILL, current, 0); + retval = -EINVAL; goto out_free_dentry; } -- 2.41.1