From 1b5d783c94c328d406e801566f161adcfb018dda Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 19 Jun 2011 12:49:47 -0400 Subject: [PATCH] consolidate BINPRM_FLAGS_ENFORCE_NONDUMP handling new helper: would_dump(bprm, file). Checks if we are allowed to read the file and if we are not - sets ENFORCE_NODUMP. Exported, used in places that previously open-coded the same logics. Signed-off-by: Al Viro --- fs/binfmt_elf.c | 3 +-- fs/binfmt_elf_fdpic.c | 3 +-- fs/binfmt_misc.c | 3 +-- fs/exec.c | 14 +++++++++++--- include/linux/binfmts.h | 1 + 5 files changed, 15 insertions(+), 9 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 303983fabfd6..dd0fdfc56d38 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -668,8 +668,7 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs) * mm->dumpable = 0 regardless of the interpreter's * permissions. */ - if (file_permission(interpreter, MAY_READ) < 0) - bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; + would_dump(bprm, interpreter); retval = kernel_read(interpreter, 0, bprm->buf, BINPRM_BUF_SIZE); diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index 2bc5dc644b4c..30745f459faf 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -245,8 +245,7 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm, * mm->dumpable = 0 regardless of the interpreter's * permissions. */ - if (file_permission(interpreter, MAY_READ) < 0) - bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; + would_dump(bprm, interpreter); retval = kernel_read(interpreter, 0, bprm->buf, BINPRM_BUF_SIZE); diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c index 1befe2ec8186..ba1a1ae4a18a 100644 --- a/fs/binfmt_misc.c +++ b/fs/binfmt_misc.c @@ -149,8 +149,7 @@ static int load_misc_binary(struct linux_binprm *bprm, struct pt_regs *regs) /* if the binary is not readable than enforce mm->dumpable=0 regardless of the interpreter's permissions */ - if (file_permission(bprm->file, MAY_READ)) - bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; + would_dump(bprm, bprm->file); allow_write_access(bprm->file); bprm->file = NULL; diff --git a/fs/exec.c b/fs/exec.c index 6075a1e727ae..f9f12ad299af 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1105,6 +1105,13 @@ out: } EXPORT_SYMBOL(flush_old_exec); +void would_dump(struct linux_binprm *bprm, struct file *file) +{ + if (inode_permission(file->f_path.dentry->d_inode, MAY_READ) < 0) + bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; +} +EXPORT_SYMBOL(would_dump); + void setup_new_exec(struct linux_binprm * bprm) { int i, ch; @@ -1144,9 +1151,10 @@ void setup_new_exec(struct linux_binprm * bprm) if (bprm->cred->uid != current_euid() || bprm->cred->gid != current_egid()) { current->pdeath_signal = 0; - } else if (file_permission(bprm->file, MAY_READ) || - bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP) { - set_dumpable(current->mm, suid_dumpable); + } else { + would_dump(bprm, bprm->file); + if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP) + set_dumpable(current->mm, suid_dumpable); } /* diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h index 8845613fd7e3..fd88a3945aa1 100644 --- a/include/linux/binfmts.h +++ b/include/linux/binfmts.h @@ -111,6 +111,7 @@ extern int __must_check remove_arg_zero(struct linux_binprm *); extern int search_binary_handler(struct linux_binprm *, struct pt_regs *); extern int flush_old_exec(struct linux_binprm * bprm); extern void setup_new_exec(struct linux_binprm * bprm); +extern void would_dump(struct linux_binprm *, struct file *); extern int suid_dumpable; #define SUID_DUMP_DISABLE 0 /* No setuid dumping */ -- 2.39.5