linux/fs
Kirill A. Shutemov bfd40eaff5 mm: fix vma_is_anonymous() false-positives
vma_is_anonymous() relies on ->vm_ops being NULL to detect anonymous
VMA.  This is unreliable as ->mmap may not set ->vm_ops.

False-positive vma_is_anonymous() may lead to crashes:

	next ffff8801ce5e7040 prev ffff8801d20eca50 mm ffff88019c1e13c0
	prot 27 anon_vma ffff88019680cdd8 vm_ops 0000000000000000
	pgoff 0 file ffff8801b2ec2d00 private_data 0000000000000000
	flags: 0xff(read|write|exec|shared|mayread|maywrite|mayexec|mayshare)
	------------[ cut here ]------------
	kernel BUG at mm/memory.c:1422!
	invalid opcode: 0000 [#1] SMP KASAN
	CPU: 0 PID: 18486 Comm: syz-executor3 Not tainted 4.18.0-rc3+ #136
	Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
	01/01/2011
	RIP: 0010:zap_pmd_range mm/memory.c:1421 [inline]
	RIP: 0010:zap_pud_range mm/memory.c:1466 [inline]
	RIP: 0010:zap_p4d_range mm/memory.c:1487 [inline]
	RIP: 0010:unmap_page_range+0x1c18/0x2220 mm/memory.c:1508
	Call Trace:
	 unmap_single_vma+0x1a0/0x310 mm/memory.c:1553
	 zap_page_range_single+0x3cc/0x580 mm/memory.c:1644
	 unmap_mapping_range_vma mm/memory.c:2792 [inline]
	 unmap_mapping_range_tree mm/memory.c:2813 [inline]
	 unmap_mapping_pages+0x3a7/0x5b0 mm/memory.c:2845
	 unmap_mapping_range+0x48/0x60 mm/memory.c:2880
	 truncate_pagecache+0x54/0x90 mm/truncate.c:800
	 truncate_setsize+0x70/0xb0 mm/truncate.c:826
	 simple_setattr+0xe9/0x110 fs/libfs.c:409
	 notify_change+0xf13/0x10f0 fs/attr.c:335
	 do_truncate+0x1ac/0x2b0 fs/open.c:63
	 do_sys_ftruncate+0x492/0x560 fs/open.c:205
	 __do_sys_ftruncate fs/open.c:215 [inline]
	 __se_sys_ftruncate fs/open.c:213 [inline]
	 __x64_sys_ftruncate+0x59/0x80 fs/open.c:213
	 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
	 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Reproducer:

	#include <stdio.h>
	#include <stddef.h>
	#include <stdint.h>
	#include <stdlib.h>
	#include <string.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <sys/ioctl.h>
	#include <sys/mman.h>
	#include <unistd.h>
	#include <fcntl.h>

	#define KCOV_INIT_TRACE			_IOR('c', 1, unsigned long)
	#define KCOV_ENABLE			_IO('c', 100)
	#define KCOV_DISABLE			_IO('c', 101)
	#define COVER_SIZE			(1024<<10)

	#define KCOV_TRACE_PC  0
	#define KCOV_TRACE_CMP 1

	int main(int argc, char **argv)
	{
		int fd;
		unsigned long *cover;

		system("mount -t debugfs none /sys/kernel/debug");
		fd = open("/sys/kernel/debug/kcov", O_RDWR);
		ioctl(fd, KCOV_INIT_TRACE, COVER_SIZE);
		cover = mmap(NULL, COVER_SIZE * sizeof(unsigned long),
				PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
		munmap(cover, COVER_SIZE * sizeof(unsigned long));
		cover = mmap(NULL, COVER_SIZE * sizeof(unsigned long),
				PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
		memset(cover, 0, COVER_SIZE * sizeof(unsigned long));
		ftruncate(fd, 3UL << 20);
		return 0;
	}

This can be fixed by assigning anonymous VMAs own vm_ops and not relying
on it being NULL.

If ->mmap() failed to set ->vm_ops, mmap_region() will set it to
dummy_vm_ops.  This way we will have non-NULL ->vm_ops for all VMAs.

Link: http://lkml.kernel.org/r/20180724121139.62570-4-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: syzbot+3f84280d52be9b7083cc@syzkaller.appspotmail.com
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-26 19:38:03 -07:00
..
9p treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
adfs vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
affs
afs Merge branch 'afs-proc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-16 16:32:04 +09:00
autofs autofs: fix slab out of bounds read in getname_kernel() 2018-07-14 11:11:09 -07:00
befs fix a series of Documentation/ broken file name references 2018-06-15 18:10:01 -03:00
bfs
btrfs for-4.18-rc5-tag 2018-07-21 16:42:03 -07:00
cachefiles cachefiles: Wait rather than BUG'ing on "Unexpected object collision" 2018-07-25 14:49:00 +01:00
ceph ceph: fix dentry leak in splice_dentry() 2018-06-26 18:42:44 +02:00
cifs cifs: Fix stack out-of-bounds in smb{2,3}_create_lease_buf() 2018-07-05 13:48:25 -05:00
coda vfs: change inode times to use struct timespec64 2018-06-05 16:57:31 -07:00
configfs vfs: change inode times to use struct timespec64 2018-06-05 16:57:31 -07:00
cramfs vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
crypto f2fs-for-4.18-rc1 2018-06-11 10:16:13 -07:00
debugfs Revert "debugfs: inode: debugfs_create_dir uses mode permission from parent" 2018-06-12 20:52:16 -07:00
devpts
dlm treewide: Use array_size() in vmalloc() 2018-06-12 16:19:22 -07:00
ecryptfs
efivarfs
efs
exofs exofs: avoid VLA in structures 2018-06-15 07:55:24 +09:00
exportfs
ext2 ext2: add warning when specifying nocheck option 2018-06-20 11:04:26 +02:00
ext4 Bug fixes for ext4; most of which relate to vulnerabilities where a 2018-07-08 11:10:30 -07:00
f2fs vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
fat fat: fix memory allocation failure handling of match_strdup() 2018-07-21 12:50:46 -07:00
freevxfs
fscache fscache: Fix reference overput in fscache_attach_object() error handling 2018-07-25 14:49:00 +01:00
fuse vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
gfs2 vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
hfs vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
hfsplus vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
hostfs vfs: change inode times to use struct timespec64 2018-06-05 16:57:31 -07:00
hpfs treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
hugetlbfs mm: use vma_init() to initialize VMAs on stack and data segments 2018-07-26 19:38:03 -07:00
isofs
jbd2 Bug fixes for ext4; most of which relate to vulnerabilities where a 2018-07-08 11:10:30 -07:00
jffs2 vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
jfs This fixes a too-small allocation in the xattr code. 2018-06-19 07:47:32 +09:00
kernfs vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
lockd
minix
nfs NFS client bugfixes for Linux 4.18 2018-06-22 06:21:34 +09:00
nfs_common
nfsd vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
nilfs2
nls
notify
ntfs vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
ocfs2 vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
omfs
openpromfs
orangefs Solve a series of broken links for files under Documentation: 2018-06-17 05:25:18 +09:00
overlayfs vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
proc fs/proc/task_mmu.c: fix Locked field in /proc/pid/smaps* 2018-07-14 11:11:09 -07:00
pstore pstore: Remove bogus format string definition 2018-06-14 14:57:24 +02:00
qnx4
qnx6
quota quota: Cleanup list iteration in dqcache_shrink_scan() 2018-06-20 11:04:26 +02:00
ramfs
reiserfs reiserfs: fix buffer overflow with long warning messages 2018-07-14 11:11:10 -07:00
romfs
squashfs
sysfs
sysv
tracefs
ubifs vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
udf udf: Drop unused arguments of udf_delete_aext() 2018-06-20 11:05:49 +02:00
ufs treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
xfs xfs: fix fdblocks accounting w/ RMAPBT per-AG reservation 2018-06-24 12:00:12 -07:00
Kconfig autofs: remove left-over autofs4 stubs 2018-06-11 08:22:34 -07:00
Kconfig.binfmt docs: Fix more broken references 2018-06-15 18:11:26 -03:00
Makefile autofs: remove left-over autofs4 stubs 2018-06-11 08:22:34 -07:00
aio.c Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-07-22 12:04:51 -07:00
anon_inodes.c
attr.c vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
bad_inode.c vfs: change inode times to use struct timespec64 2018-06-05 16:57:31 -07:00
binfmt_aout.c
binfmt_elf.c fs, elf: make sure to page align bss in load_elf_library 2018-07-14 11:11:10 -07:00
binfmt_elf_fdpic.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c docs: Fix more broken references 2018-06-15 18:11:26 -03:00
binfmt_script.c
block_dev.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
buffer.c
char_dev.c
compat.c
compat_binfmt_elf.c
compat_ioctl.c autofs: clean up includes 2018-06-07 17:34:40 -07:00
coredump.c
d_path.c
dax.c libnvdimm for 4.18 2018-06-08 17:21:52 -07:00
dcache.c
dcookies.c
direct-io.c
drop_caches.c
eventfd.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
eventpoll.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
exec.c mm: fix vma_is_anonymous() false-positives 2018-07-26 19:38:03 -07:00
fcntl.c mm: restructure memfd code 2018-06-07 17:34:35 -07:00
fhandle.c
file.c
file_table.c
filesystems.c
fs-writeback.c
fs_pin.c
fs_struct.c
inode.c Fix up non-directory creation in SGID directories 2018-07-05 12:36:36 -07:00
internal.h drm_mode_create_lease_ioctl(): fix open-coded filp_clone_open() 2018-07-10 23:29:03 -04:00
ioctl.c
iomap.c Changes since last update: 2018-06-12 15:49:00 -07:00
libfs.c
locks.c vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
mbcache.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
mount.h
mpage.c
namei.c Merge branch 'afs-proc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-16 16:32:04 +09:00
namespace.c
no-block.c
nsfs.c
open.c
pipe.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
pnode.c
pnode.h
posix_acl.c
proc_namespace.c
read_write.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
readdir.c
select.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
seq_file.c
signalfd.c Merge branch 'work.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-16 16:21:50 +09:00
splice.c Merge branch 'work.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-16 16:21:50 +09:00
stack.c
stat.c
statfs.c
super.c
sync.c
timerfd.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
userfaultfd.c userfaultfd: hugetlbfs: fix userfaultfd_huge_must_wait() pte access 2018-07-03 17:32:18 -07:00
utimes.c
xattr.c