linux-stable/include/linux/coredump.h
Eric W. Biederman 390031c942 coredump: Use the vma snapshot in fill_files_note
Matthew Wilcox reported that there is a missing mmap_lock in
file_files_note that could possibly lead to a user after free.

Solve this by using the existing vma snapshot for consistency
and to avoid the need to take the mmap_lock anywhere in the
coredump code except for dump_vma_snapshot.

Update the dump_vma_snapshot to capture vm_pgoff and vm_file
that are neeeded by fill_files_note.

Add free_vma_snapshot to free the captured values of vm_file.

Reported-by: Matthew Wilcox <willy@infradead.org>
Link: https://lkml.kernel.org/r/20220131153740.2396974-1-willy@infradead.org
Cc: stable@vger.kernel.org
Fixes: a07279c9a8 ("binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot")
Fixes: 2aa362c49c ("coredump: extend core dump note section to contain file names of mapped files")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-03-08 13:04:19 -06:00

54 lines
1.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_COREDUMP_H
#define _LINUX_COREDUMP_H
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <asm/siginfo.h>
#ifdef CONFIG_COREDUMP
struct core_vma_metadata {
unsigned long start, end;
unsigned long flags;
unsigned long dump_size;
unsigned long pgoff;
struct file *file;
};
struct coredump_params {
const kernel_siginfo_t *siginfo;
struct pt_regs *regs;
struct file *file;
unsigned long limit;
unsigned long mm_flags;
loff_t written;
loff_t pos;
loff_t to_skip;
int vma_count;
size_t vma_data_size;
struct core_vma_metadata *vma_meta;
};
/*
* These are the only things you should do on a core-file: use only these
* functions to write out all the necessary info.
*/
extern void dump_skip_to(struct coredump_params *cprm, unsigned long to);
extern void dump_skip(struct coredump_params *cprm, size_t nr);
extern int dump_emit(struct coredump_params *cprm, const void *addr, int nr);
extern int dump_align(struct coredump_params *cprm, int align);
int dump_user_range(struct coredump_params *cprm, unsigned long start,
unsigned long len);
extern void do_coredump(const kernel_siginfo_t *siginfo);
#else
static inline void do_coredump(const kernel_siginfo_t *siginfo) {}
#endif
#if defined(CONFIG_COREDUMP) && defined(CONFIG_SYSCTL)
extern void validate_coredump_safety(void);
#else
static inline void validate_coredump_safety(void) {}
#endif
#endif /* _LINUX_COREDUMP_H */