From 30736a4d43f4af7f1a7836d6a266be17082195c4 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Fri, 5 Mar 2010 13:44:12 -0800 Subject: coredump: pass mm->flags as a coredump parameter for consistency Pass mm->flags as a coredump parameter for consistency. --- 1787 if (mm->core_state || !get_dumpable(mm)) { <- (1) 1788 up_write(&mm->mmap_sem); 1789 put_cred(cred); 1790 goto fail; 1791 } 1792 [...] 1798 if (get_dumpable(mm) == 2) { /* Setuid core dump mode */ <-(2) 1799 flag = O_EXCL; /* Stop rewrite attacks */ 1800 cred->fsuid = 0; /* Dump root private */ 1801 } --- Since dumpable bits are not protected by lock, there is a chance to change these bits between (1) and (2). To solve this issue, this patch copies mm->flags to coredump_params.mm_flags at the beginning of do_coredump() and uses it instead of get_dumpable() while dumping core. This copy is also passed to binfmt->core_dump, since elf*_core_dump() uses dump_filter bits in mm->flags. [akpm@linux-foundation.org: fix merge] Signed-off-by: Masami Hiramatsu Acked-by: Roland McGrath Cc: Hidehiro Kawai Cc: Oleg Nesterov Cc: Ingo Molnar Reviewed-by: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/binfmts.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/binfmts.h') diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h index 89c6249fc561..c809e286d213 100644 --- a/include/linux/binfmts.h +++ b/include/linux/binfmts.h @@ -74,6 +74,7 @@ struct coredump_params { struct pt_regs *regs; struct file *file; unsigned long limit; + unsigned long mm_flags; }; /* -- cgit v1.2.3-59-g8ed1b