Luis Chamberlain 480534e030 coredump: fix crash when umh is disabled ... commit 3740d93e37 upstream. Commit 64e90a8acb ("Introduce STATIC_USERMODEHELPER to mediate call_usermodehelper()") added the optiont to disable all call_usermodehelper() calls by setting STATIC_USERMODEHELPER_PATH to an empty string. When this is done, and crashdump is triggered, it will crash on null pointer dereference, since we make assumptions over what call_usermodehelper_exec() did. This has been reported by Sergey when one triggers a a coredump with the following configuration: ``` CONFIG_STATIC_USERMODEHELPER=y CONFIG_STATIC_USERMODEHELPER_PATH="" kernel.core_pattern = |/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h %e ``` The way disabling the umh was designed was that call_usermodehelper_exec() would just return early, without an error. But coredump assumes certain variables are set up for us when this happens, and calls ile_start_write(cprm.file) with a NULL file. [ 2.819676] BUG: kernel NULL pointer dereference, address: 0000000000000020 [ 2.819859] #PF: supervisor read access in kernel mode [ 2.820035] #PF: error_code(0x0000) - not-present page [ 2.820188] PGD 0 P4D 0 [ 2.820305] Oops: 0000 [#1] SMP PTI [ 2.820436] CPU: 2 PID: 89 Comm: a Not tainted 5.7.0-rc1+ #7 [ 2.820680] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190711_202441-buildvm-armv7-10.arm.fedoraproject.org-2.fc31 04/01/2014 [ 2.821150] RIP: 0010:do_coredump+0xd80/0x1060 [ 2.821385] Code: e8 95 11 ed ff 48 c7 c6 cc a7 b4 81 48 8d bd 28 ff ff ff 89 c2 e8 70 f1 ff ff 41 89 c2 85 c0 0f 84 72 f7 ff ff e9 b4 fe ff ff <48> 8b 57 20 0f b7 02 66 25 00 f0 66 3d 00 8 0 0f 84 9c 01 00 00 44 [ 2.822014] RSP: 0000:ffffc9000029bcb8 EFLAGS: 00010246 [ 2.822339] RAX: 0000000000000000 RBX: ffff88803f860000 RCX: 000000000000000a [ 2.822746] RDX: 0000000000000009 RSI: 0000000000000282 RDI: 0000000000000000 [ 2.823141] RBP: ffffc9000029bde8 R08: 0000000000000000 R09: ffffc9000029bc00 [ 2.823508] R10: 0000000000000001 R11: ffff88803dec90be R12: ffffffff81c39da0 [ 2.823902] R13: ffff88803de84400 R14: 0000000000000000 R15: 0000000000000000 [ 2.824285] FS: 00007fee08183540(0000) GS:ffff88803e480000(0000) knlGS:0000000000000000 [ 2.824767] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2.825111] CR2: 0000000000000020 CR3: 000000003f856005 CR4: 0000000000060ea0 [ 2.825479] Call Trace: [ 2.825790] get_signal+0x11e/0x720 [ 2.826087] do_signal+0x1d/0x670 [ 2.826361] ? force_sig_info_to_task+0xc1/0xf0 [ 2.826691] ? force_sig_fault+0x3c/0x40 [ 2.826996] ? do_trap+0xc9/0x100 [ 2.827179] exit_to_usermode_loop+0x49/0x90 [ 2.827359] prepare_exit_to_usermode+0x77/0xb0 [ 2.827559] ? invalid_op+0xa/0x30 [ 2.827747] ret_from_intr+0x20/0x20 [ 2.827921] RIP: 0033:0x55e2c76d2129 [ 2.828107] Code: 2d ff ff ff e8 68 ff ff ff 5d c6 05 18 2f 00 00 01 c3 0f 1f 80 00 00 00 00 c3 0f 1f 80 00 00 00 00 e9 7b ff ff ff 55 48 89 e5 <0f> 0b b8 00 00 00 00 5d c3 66 2e 0f 1f 84 0 0 00 00 00 00 0f 1f 40 [ 2.828603] RSP: 002b:00007fffeba5e080 EFLAGS: 00010246 [ 2.828801] RAX: 000055e2c76d2125 RBX: 0000000000000000 RCX: 00007fee0817c718 [ 2.829034] RDX: 00007fffeba5e188 RSI: 00007fffeba5e178 RDI: 0000000000000001 [ 2.829257] RBP: 00007fffeba5e080 R08: 0000000000000000 R09: 00007fee08193c00 [ 2.829482] R10: 0000000000000009 R11: 0000000000000000 R12: 000055e2c76d2040 [ 2.829727] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 2.829964] CR2: 0000000000000020 [ 2.830149] ---[ end trace ceed83d8c68a1bf1 ]--- ``` Cc: <stable@vger.kernel.org> # v4.11+ Fixes: 64e90a8acb ("Introduce STATIC_USERMODEHELPER to mediate call_usermodehelper()") BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=199795 Reported-by: Tony Vroon <chainsaw@gentoo.org> Reported-by: Sergey Kvachonok <ravenexp@gmail.com> Tested-by: Sergei Trofimovich <slyfox@gentoo.org> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20200416162859.26518-1-mcgrof@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2020-05-14 07:58:27 +02:00
..
9p	9p pull request for inclusion in 5.4	2019-09-27 15:10:34 -07:00
adfs	Merge branch 'work.adfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-07-19 11:33:22 -07:00
affs	affs: fix a memory leak in affs_remount	2020-01-17 19:48:50 +01:00
afs	afs: Fix length of dump of bad YFSFetchStatus record	2020-05-02 08:48:55 +02:00
autofs	autofs: fix a leak in autofs_expire_indirect()	2019-10-25 00:03:11 -04:00
befs	fs: Fill in max and min timestamps in superblock	2019-08-30 07:27:17 -07:00
bfs	fs: Fill in max and min timestamps in superblock	2019-08-30 07:27:17 -07:00
btrfs	btrfs: transaction: Avoid deadlock due to bad initialization timing of fs_info::journal_info	2020-05-06 08:15:06 +02:00
cachefiles	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36	2019-05-24 17:27:11 +02:00
ceph	ceph: demote quotarealm lookup warning to a debug message	2020-05-14 07:58:27 +02:00
cifs	cifs: do not share tcons with DFS	2020-05-10 10:31:27 +02:00
coda	y2038: add inode timestamp clamping	2019-09-19 09:42:37 -07:00
configfs	utimes: Clamp the timestamps in notify_change()	2020-02-11 04:35:12 -08:00
cramfs	cramfs: fix usage on non-MTD device	2019-11-23 21:44:49 -05:00
crypto	fscrypt: don't evict dirty inodes after removing key	2020-03-18 07:17:53 +01:00
debugfs	debugfs: Check module state before warning in {full/open}_proxy_open()	2020-04-17 10:50:02 +02:00
devpts	devpts_pty_kill(): don't bother with d_delete()	2019-09-03 09:30:56 -04:00
dlm	dlm for 5.3	2019-07-12 17:37:53 -07:00
ecryptfs	ecryptfs: replace BUG_ON with error handling code	2020-02-28 17:22:26 +01:00
efivarfs	Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-07-19 10:42:02 -07:00
efs	fs: Fill in max and min timestamps in superblock	2019-08-30 07:27:17 -07:00
erofs	erofs: correct the remaining shrink objects	2020-04-17 10:50:16 +02:00
exportfs	exportfs_decode_fh(): negative pinned may become positive without the parent locked	2019-11-10 11:56:05 -05:00
ext2	ext2: fix debug reference to ext2_xattr_cache	2020-04-23 10:36:41 +02:00
ext4	ext4: check for non-zero journal inum in ext4_calculate_overhead	2020-05-02 08:49:01 +02:00
f2fs	f2fs: fix to avoid memory leakage in f2fs_listxattr	2020-04-29 16:32:55 +02:00
fat	fat: fix uninit-memory access for partial initialized inode	2020-03-12 13:00:19 +01:00
freevxfs	fs: Fill in max and min timestamps in superblock	2019-08-30 07:27:17 -07:00
fscache	Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs"	2019-07-10 18:43:43 -07:00
fuse	fuse: fix stack use after return	2020-03-18 07:17:52 +01:00
gfs2	gfs2: Don't demote a glock until its revokes are written	2020-04-17 10:50:03 +02:00
hfs	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
hfsplus	hfsplus: fix crash and filesystem corruption when deleting files	2020-04-17 10:50:22 +02:00
hostfs	This pull request contains the following changes for UML:	2019-05-12 17:52:13 -04:00
hpfs	fs: hpfs: Initialize filesystem timestamp ranges	2019-08-30 08:11:25 -07:00
hugetlbfs	mm/hugetlbfs: fix for_each_hstate() loop in init_hugetlbfs_fs()	2020-01-04 19:19:19 +01:00
iomap	iomap: fix return value of iomap_dio_bio_actor on 32bit systems	2020-01-04 19:17:31 +01:00
isofs	y2038: add inode timestamp clamping	2019-09-19 09:42:37 -07:00
jbd2	jbd2: improve comments about freeing data buffers whose page mapping is NULL	2020-04-21 09:04:52 +02:00
jffs2	Revert "jffs2: Fix possible null-pointer dereferences in jffs2_add_frag_to_fragtree()"	2019-12-04 22:31:06 +01:00
jfs	y2038: add inode timestamp clamping	2019-09-19 09:42:37 -07:00
kernfs	kernfs: fix ino wrap-around detection	2019-12-13 08:42:53 +01:00
lockd	lockd: Make two symbols static	2019-07-03 17:52:09 -04:00
minix	fs: Fill in max and min timestamps in superblock	2019-08-30 07:27:17 -07:00
nfs	nfs: Fix potential posix_acl refcnt leak in nfs3_set_acl	2020-05-06 08:15:16 +02:00
nfs_common	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
nfsd	nfsd: memory corruption in nfsd4_lock()	2020-05-02 08:48:46 +02:00
nilfs2	vfs: create a generic checking and prep function for FS_IOC_SETFLAGS	2019-07-01 08:25:34 -07:00
nls	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
notify	fs: call fsnotify_sb_delete after evict_inodes	2020-01-12 12:21:38 +01:00
ntfs	utimes: Clamp the timestamps in notify_change()	2020-02-11 04:35:12 -08:00
ocfs2	dlmfs_file_write(): fix the bogosity in handling non-zero *ppos	2020-05-06 08:15:09 +02:00
omfs	fs: omfs: Initialize filesystem timestamp ranges	2019-08-30 08:11:25 -07:00
openpromfs	Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-07-19 10:42:02 -07:00
orangefs	help_next should increase position index	2020-02-24 08:37:02 +01:00
overlayfs	ovl: fix value of i_ino for lower hardlink corner case	2020-04-21 09:04:50 +02:00
proc	vmalloc: fix remap_vmalloc_range() bounds checks	2020-04-29 16:33:14 +02:00
pstore	pstore: pstore_ftrace_seq_next should increase position index	2020-04-17 10:50:12 +02:00
qnx4	fs: Fill in max and min timestamps in superblock	2019-08-30 07:27:17 -07:00
qnx6	fs: Fill in max and min timestamps in superblock	2019-08-30 07:27:17 -07:00
quota	fs: avoid softlockups in s_inodes iterators	2020-01-12 12:21:37 +01:00
ramfs	vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API	2019-09-12 21:05:34 -04:00
reiserfs	reiserfs: prevent NULL pointer dereference in reiserfs_insert_item()	2020-02-24 08:37:00 +01:00
romfs	Merge branch 'work.mount2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-09-19 10:06:57 -07:00
squashfs	Merge branch 'work.mount2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-09-19 10:06:57 -07:00
sysfs	Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-07-19 10:42:02 -07:00
sysv	fs: sysv: Initialize filesystem timestamp ranges	2019-08-30 07:27:18 -07:00
tracefs	tracing: Do not create tracefs files if tracefs lockdown is in effect	2019-10-12 20:49:07 -04:00
ubifs	ubifs: Fix ubifs_tnc_lookup() usage in do_kill_orphans()	2020-05-02 08:48:42 +02:00
udf	udf: Fix free space reporting for metadata and virtual partitions	2020-02-24 08:36:44 +01:00
ufs	y2038: add inode timestamp clamping	2019-09-19 09:42:37 -07:00
unicode	unicode: make array 'token' static const, makes object smaller	2019-09-17 11:48:24 -04:00
verity	fs-verity: support builtin file signatures	2019-08-12 19:33:50 -07:00
xfs	xfs: fix partially uninitialized structure in xfs_reflink_remap_extent	2020-05-02 08:48:56 +02:00
Kconfig	fs-verity for 5.4	2019-09-18 16:59:14 -07:00
Kconfig.binfmt	binfmt_flat: make support for old format binaries optional	2019-06-24 09:16:47 +10:00
Makefile	fs-verity for 5.4	2019-09-18 16:59:14 -07:00
aio.c	aio: prevent potential eventfd recursion on poll	2020-02-11 04:35:37 -08:00
anon_inodes.c	Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-07-19 10:42:02 -07:00
attr.c	utimes: Clamp the timestamps in notify_change()	2020-02-11 04:35:12 -08:00
bad_inode.c	…
binfmt_aout.c	treewide: Add SPDX license identifier for more missed files	2019-05-21 10:50:45 +02:00
binfmt_elf.c	elf: don't use MAP_FIXED_NOREPLACE for elf executable mappings	2019-10-06 13:53:27 -07:00
binfmt_elf_fdpic.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152	2019-05-30 11:26:32 -07:00
binfmt_em86.c	treewide: Add SPDX license identifier for more missed files	2019-05-21 10:50:45 +02:00
binfmt_flat.c	fs/binfmt_flat.c: remove set but not used variable 'inode'	2019-07-16 19:23:22 -07:00
binfmt_misc.c	Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-07-19 10:42:02 -07:00
binfmt_script.c	treewide: Add SPDX license identifier for more missed files	2019-05-21 10:50:45 +02:00
block_dev.c	hibernate: Allow uswsusp to write to swap	2020-04-23 10:36:34 +02:00
buffer.c	ext4: use non-movable memory for superblock readahead	2020-04-23 10:36:15 +02:00
char_dev.c	chardev: Avoid potential use-after-free in 'chrdev_open()'	2020-01-14 20:08:18 +01:00
compat.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
compat_binfmt_elf.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 193	2019-05-30 11:29:21 -07:00
compat_ioctl.c	fix compat handling of FICLONERANGE, FIDEDUPERANGE and FS_IOC_FIEMAP	2020-01-09 10:20:05 +01:00
coredump.c	coredump: fix crash when umh is disabled	2020-05-14 07:58:27 +02:00
d_path.c	[PATCH] fix d_absolute_path() interplay with fsmount()	2019-08-30 19:31:09 -04:00
dax.c	dax: pass NOWAIT flag to iomap_apply	2020-03-05 16:43:36 +01:00
dcache.c	Merge branch 'work.dcache2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-07-20 09:15:51 -07:00
dcookies.c	treewide: Add SPDX license identifier for missed files	2019-05-21 10:50:45 +02:00
direct-io.c	fs/direct-io.c: fix kernel-doc warning	2019-10-14 15:04:01 -07:00
drop_caches.c	fs: avoid softlockups in s_inodes iterators	2020-01-12 12:21:37 +01:00
eventfd.c	eventfd: track eventfd_signal() recursion depth	2020-02-11 04:35:37 -08:00
eventpoll.c	eventpoll: fix missing wakeup for ovflist in ep_poll_callback	2020-05-14 07:58:26 +02:00
exec.c	signal: Extend exec_id to 64bits	2020-04-17 10:50:12 +02:00
fcntl.c	…
fhandle.c	fs/handle.c - fix up kerneldoc	2019-08-07 21:51:47 -04:00
file.c	…
file_table.c	vfs: Export flush_delayed_fput for use by knfsd.	2019-08-19 11:00:39 -04:00
filesystems.c	fs/filesystems.c: downgrade user-reachable WARN_ONCE() to pr_warn_once()	2020-04-17 10:50:21 +02:00
fs-writeback.c	memcg: fix a crash in wb_workfn when a device disappears	2020-02-11 04:35:11 -08:00
fs_context.c	vfs: subtype handling moved to fuse	2019-09-06 21:28:49 +02:00
fs_parser.c	vfs: Make fs_parse() handle fs_param_is_fd-type params better	2019-09-12 21:06:14 -04:00
fs_pin.c	switch the remnants of releasing the mountpoint away from fs_pin	2019-07-16 22:52:37 -04:00
fs_struct.c	treewide: Add SPDX license identifier for missed files	2019-05-21 10:50:45 +02:00
fs_types.c	…
fsopen.c	Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-07-19 10:42:02 -07:00
inode.c	futex: Fix inode life-time issue	2020-03-25 08:25:58 +01:00
internal.h	fs: move guard_bio_eod() after bio_set_op_attrs	2020-01-17 19:48:21 +01:00
io_uring.c	io_uring: honor original task RLIMIT_FSIZE	2020-04-17 10:50:16 +02:00
ioctl.c	compat_ioctl: add compat_ptr_ioctl()	2019-12-17 19:55:30 +01:00
libfs.c	libfs: fix infoleak in simple_attr_read()	2020-04-01 11:02:17 +02:00
locks.c	locks: reinstate locks_delete_block optimization	2020-03-25 08:25:41 +01:00
mbcache.c	treewide: Add SPDX license identifier for more missed files	2019-05-21 10:50:45 +02:00
mount.h	switch the remnants of releasing the mountpoint away from fs_pin	2019-07-16 22:52:37 -04:00
mpage.c	fs: move guard_bio_eod() after bio_set_op_attrs	2020-01-17 19:48:21 +01:00
namei.c	namei: only return -ECHILD from follow_dotdot_rcu()	2020-03-05 16:43:48 +01:00
namespace.c	fs/namespace.c: fix use-after-free of mount in mnt_warn_timestamp_expiry()	2019-10-16 23:15:09 -04:00
no-block.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152	2019-05-30 11:26:32 -07:00
nsfs.c	vfs: Convert nsfs to use the new mount API	2019-05-25 18:00:06 -04:00
open.c	cifs_atomic_open(): fix double-put on late allocation failure	2020-03-18 07:17:51 +01:00
pipe.c	vfs: Convert pipe to use the new mount API	2019-05-25 18:00:07 -04:00
pnode.c	propagate_one(): mnt_set_mountpoint() needs mount_lock	2020-05-02 08:48:44 +02:00
pnode.h	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 209	2019-05-30 11:29:53 -07:00
posix_acl.c	treewide: Add SPDX license identifier for missed files	2019-05-21 10:50:45 +02:00
proc_namespace.c	vfs: subtype handling moved to fuse	2019-09-06 21:28:49 +02:00
read_write.c	fs: allow deduplication of eof block into the end of the destination file	2020-02-11 04:35:23 -08:00
readdir.c	readdir: be more conservative with directory entry names	2020-01-29 16:45:31 +01:00
select.c	fs/select.c: use struct_size() in kmalloc()	2019-07-16 19:23:25 -07:00
seq_file.c	seq_file: fix problem when seeking mid-record	2019-08-13 16:06:52 -07:00
signalfd.c	…
splice.c	splice: only read in as much information as there is pipe buffer space	2019-12-17 19:56:52 +01:00
stack.c	treewide: Add SPDX license identifier for missed files	2019-05-21 10:50:45 +02:00
stat.c	…
statfs.c	vfs: Fix EOVERFLOW testing in put_compat_statfs64	2019-10-03 14:21:35 -07:00
super.c	Fix use after free in get_tree_bdev()	2020-05-06 08:15:15 +02:00
sync.c	fs/sync.c: sync_file_range(2) may use WB_SYNC_ALL writeback	2019-05-14 09:47:50 -07:00
timerfd.c	timerfd: Prepare for PREEMPT_RT	2019-08-01 20:51:23 +02:00
userfaultfd.c	userfaultfd: require CAP_SYS_PTRACE for UFFD_FEATURE_EVENT_FORK	2020-01-04 19:18:32 +01:00
utimes.c	utimes: Clamp the timestamps in notify_change()	2020-02-11 04:35:12 -08:00
xattr.c	treewide: Add SPDX license identifier for missed files	2019-05-21 10:50:45 +02:00