2.6.27.59-stable review patch. If anyone has any objections, please let us know.
------------------ From: Oleg Nesterov <[email protected]> commit 114279be2120a916e8a04feeb2ac976a10016f2f upstream. Note: this patch targets 2.6.37 and tries to be as simple as possible. That is why it adds more copy-and-paste horror into fs/compat.c and uglifies fs/exec.c, this will be cleanuped later. compat_copy_strings() plays with bprm->vma/mm directly and thus has two problems: it lacks the RLIMIT_STACK check and argv/envp memory is not visible to oom killer. Export acct_arg_size() and get_arg_page(), change compat_copy_strings() to use get_arg_page(), change compat_do_execve() to do acct_arg_size(0) as do_execve() does. Add the fatal_signal_pending/cond_resched checks into compat_count() and compat_copy_strings(), this matches the code in fs/exec.c and certainly makes sense. Signed-off-by: Oleg Nesterov <[email protected]> Cc: KOSAKI Motohiro <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Andi Kleen <[email protected]> Cc: Moritz Muehlenhoff <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/compat.c | 28 +++++++++++++++------------- fs/exec.c | 8 ++++---- include/linux/binfmts.h | 4 ++++ 3 files changed, 23 insertions(+), 17 deletions(-) Index: longterm-2.6.27/fs/compat.c =================================================================== --- longterm-2.6.27.orig/fs/compat.c 2011-01-23 10:52:28.000000000 +0100 +++ longterm-2.6.27/fs/compat.c 2011-04-25 17:24:25.210282944 +0200 @@ -1241,6 +1241,10 @@ argv++; if(++i > max) return -E2BIG; + + if (fatal_signal_pending(current)) + return -ERESTARTNOHAND; + cond_resched(); } } return i; @@ -1282,6 +1286,12 @@ while (len > 0) { int offset, bytes_to_copy; + if (fatal_signal_pending(current)) { + ret = -ERESTARTNOHAND; + goto out; + } + cond_resched(); + offset = pos % PAGE_SIZE; if (offset == 0) offset = PAGE_SIZE; @@ -1298,18 +1308,8 @@ if (!kmapped_page || kpos != (pos & PAGE_MASK)) { struct page *page; -#ifdef CONFIG_STACK_GROWSUP - ret = expand_stack_downwards(bprm->vma, pos); - if (ret < 0) { - /* We've exceed the stack rlimit. */ - ret = -E2BIG; - goto out; - } -#endif - ret = get_user_pages(current, bprm->mm, pos, - 1, 1, 1, &page, NULL); - if (ret <= 0) { - /* We've exceed the stack rlimit. */ + page = get_arg_page(bprm, pos, 1); + if (!page) { ret = -E2BIG; goto out; } @@ -1425,8 +1425,10 @@ security_bprm_free(bprm); out_mm: - if (bprm->mm) + if (bprm->mm) { + acct_arg_size(bprm, 0); mmput(bprm->mm); + } out_file: if (bprm->file) { Index: longterm-2.6.27/fs/exec.c =================================================================== --- longterm-2.6.27.orig/fs/exec.c 2011-04-25 17:22:50.000000000 +0200 +++ longterm-2.6.27/fs/exec.c 2011-04-25 17:23:56.746278475 +0200 @@ -168,7 +168,7 @@ #ifdef CONFIG_MMU -static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) +void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) { struct mm_struct *mm = current->mm; long diff = (long)(pages - bprm->vma_pages); @@ -183,7 +183,7 @@ up_write(&mm->mmap_sem); } -static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, +struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, int write) { struct page *page; @@ -308,11 +308,11 @@ #else -static inline void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) +void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) { } -static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, +struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, int write) { struct page *page; Index: longterm-2.6.27/include/linux/binfmts.h =================================================================== --- longterm-2.6.27.orig/include/linux/binfmts.h 2011-04-25 17:22:24.000000000 +0200 +++ longterm-2.6.27/include/linux/binfmts.h 2011-04-25 17:23:56.751278452 +0200 @@ -53,6 +53,10 @@ unsigned long loader, exec; }; +extern void acct_arg_size(struct linux_binprm *bprm, unsigned long pages); +extern struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, + int write); + #define BINPRM_FLAGS_ENFORCE_NONDUMP_BIT 0 #define BINPRM_FLAGS_ENFORCE_NONDUMP (1 << BINPRM_FLAGS_ENFORCE_NONDUMP_BIT) _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
