Eric Biggers
696119fa9f
libfs: fix infoleak in simple_attr_read() ...
commit a65cab7d7f05c2061a3e2490257d3086ff3202c6 upstream.
Reading from a debugfs file at a nonzero position, without first reading
at position 0, leaks uninitialized memory to userspace.
It's a bit tricky to do this, since lseek() and pread() aren't allowed
on these files, and write() doesn't update the position on them. But
writing to them with splice() *does* update the position:
#define _GNU_SOURCE 1
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
int main()
{
int pipes[2], fd, n, i;
char buf[32];
pipe(pipes);
write(pipes[1], "0", 1);
fd = open("/sys/kernel/debug/fault_around_bytes", O_RDWR);
splice(pipes[0], NULL, fd, NULL, 1, 0);
n = read(fd, buf, sizeof(buf));
for (i = 0; i < n; i++)
printf("%02x", buf[i]);
printf("\n");
}
Output:
5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a30
Fix the infoleak by making simple_attr_read() always fill
simple_attr::get_buf if it hasn't been filled yet.
Reported-by: syzbot+fcab69d1ada3e8d6f06b@syzkaller.appspotmail.com
Reported-by: Alexander Potapenko <glider@google.com>
Fixes: acaefc25d2stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200308023849.988264-1-ebiggers@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-02 17:20:38 +02:00
9p: avoid attaching writeback_fid on mmap with type PRIVATE
2019-10-17 13:42:10 -07:00
fs/adfs: super: fix use-after-free bug
2019-08-06 18:29:35 +02:00
affs_lookup(): close a race with affs_remove_link()
2018-05-30 07:50:16 +02:00
afs: Fix large file support
2020-01-29 10:24:34 +01:00
autofs: fix a leak in autofs_expire_indirect()
2019-12-21 10:40:46 +01:00
befs fixes for 4.9-rc1
2016-10-15 12:09:13 -07:00
bfs: add sanity check at bfs_fill_super()
2018-12-01 09:44:19 +01:00
Btrfs: fix btrfs_wait_ordered_range() so that it waits for all ordered extents
2020-02-28 15:42:53 +01:00
fscache, cachefiles: remove redundant variable 'cache'
2018-12-17 09:38:34 +01:00
ceph: fix dentry leak in ceph_readdir_prepopulate
2019-11-28 18:28:34 +01:00
cifs_atomic_open(): fix double-put on late allocation failure
2020-03-20 09:07:44 +01:00
coda: add error handling for fget
2019-08-06 18:29:38 +02:00
configfs: fix a deadlock in configfs_symlink()
2019-11-12 19:15:51 +01:00
Cramfs: fix abad comparison when wrap-arounds occur
2018-11-13 11:17:03 -08:00
fscrypt: don't set policy for a dead directory
2019-07-21 09:05:59 +02:00
debugfs: fix use-after-free on symlink traversal
2019-05-08 07:19:10 +02:00
fs/devpts: always delete dcache dentry-s in dput()
2019-03-23 13:19:47 +01:00
dlm: fix invalid cluster name warning
2019-12-21 10:41:21 +01:00
ecryptfs: Fix up bad backport of fe2e082f5da5b4a0a92ae32978f81507ef37ec66
2020-03-11 07:53:06 +01:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2016-10-10 20:16:43 -07:00
fs/exofs: fix potential memory leak in mount option parsing
2018-11-27 16:09:38 +01:00
exportfs: fix 'passing zero to ERR_PTR()' warning
2020-01-29 10:24:03 +01:00
ext2: Adjust indentation in ext2_fill_super
2020-02-14 16:31:05 -05:00
ext4: potential crash on allocation error in ext4_alloc_flex_bg_array()
2020-03-11 07:53:05 +01:00
f2fs: fix potential overflow
2020-01-23 08:19:37 +01:00
fat: fix uninit-memory access for partial initialized inode
2020-03-11 07:53:11 +01:00
fscache: fix race between enablement and dropping of object
2018-12-17 09:38:34 +01:00
fuse: verify attributes
2019-12-21 10:41:30 +01:00
gfs2_atomic_open(): fix O_EXCL|O_CREAT handling on cold dcache
2020-03-20 09:07:44 +01:00
fs/hfs/extent.c: fix array out of bounds read of array extent
2019-11-28 18:28:50 +01:00
hfsplus: update timestamps on truncate()
2019-11-28 18:28:49 +01:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2016-10-10 20:16:43 -07:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2016-10-10 20:16:43 -07:00
hugetlb: use same fault hash key for shared and private mappings
2019-05-31 06:48:12 -07:00
isofs: fix timestamps beyond 2027
2017-11-30 08:39:04 +00:00
jbd2: fix data races at struct journal_head
2020-03-20 09:07:58 +01:00
jffs2: fix use-after-free on symlink traversal
2019-05-08 07:19:09 +02:00
jfs: fix bogus variable self-initialization
2020-01-29 10:24:19 +01:00
kernfs: Fix range checks in kernfs_get_target_path
2019-11-25 09:52:23 +01:00
lockd: fix access beyond unterminated strings in prints
2018-11-13 11:17:02 -08:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2016-10-10 20:16:43 -07:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2016-10-10 20:16:43 -07:00
ncpfs: fix build warning of strncpy
2019-03-13 14:04:52 -07:00
NFS: Remove superfluous kmap in nfs_readdir_xdr_to_array
2020-03-20 09:07:37 +01:00
lockd: fix "list_add double add" caused by legacy signal interface
2018-02-03 17:05:38 +01:00
nfsd: fix jiffies/time_t mixup in LRU list
2020-02-14 16:31:06 -05:00
do d_instantiate/unlock_new_inode combinations safely
2018-05-30 07:50:16 +02:00
fanotify: fix handling of events on child sub-directory
2019-02-06 17:33:30 +01:00
fs: remove the never implemented aio_fsync file operation
2016-10-30 13:09:42 -04:00
ocfs2: fix a NULL pointer dereference when call ocfs2_update_inode_fsync_trans()
2020-02-28 15:42:41 +01:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2016-10-10 20:16:43 -07:00
fs: Replace CURRENT_TIME with current_time() for inode timestamps
2016-09-27 21:06:21 -04:00
help_next should increase position index
2020-02-28 15:42:43 +01:00
ovl: filter of trusted xattr results in audit
2019-10-05 12:30:34 +02:00
proc/vmcore: Fix i386 build error of missing copy_oldmem_page_encrypted()
2019-11-25 09:53:44 +01:00
pstore/ram: Write new dumps to start of recycled zones
2020-01-12 11:24:20 +01:00
fs/quota: handle overflows of sysctl fs.quota.* and report as unsigned long
2020-01-04 13:40:50 +01:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2016-10-10 20:16:43 -07:00
reiserfs: prevent NULL pointer dereference in reiserfs_insert_item()
2020-02-28 15:42:41 +01:00
romfs: use different way to generate fsid for BLOCK or MTD
2017-06-17 06:41:56 +02:00
Squashfs: Compute expected length from inode size rather than block length
2018-09-05 09:20:03 +02:00
scsi: sysfs: Introduce sysfs_{un,}break_active_protection()
2018-09-05 09:20:10 +02:00
sysv: return 'err' instead of 0 in __sysv_write_inode
2018-12-17 09:38:32 +01:00
fs: Replace CURRENT_TIME with current_time() for inode timestamps
2016-09-27 21:06:21 -04:00
ubifs: Fix deadlock in concurrent bulk-read and writepage
2020-02-14 16:31:00 -05:00
udf: Fix free space reporting for metadata and virtual partitions
2020-02-28 15:42:30 +01:00
ufs: fix braino in ufs_get_inode_gid() for solaris UFS flavour
2019-05-25 18:26:56 +02:00
xfs: Sanity check flags of Q_XQUOTARM call
2020-01-29 10:24:00 +01:00
aio: fix spectre gadget in lookup_ioctx
2018-12-21 14:11:31 +01:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2016-10-10 20:16:43 -07:00
bad_inode: add missing i_op initializers
2017-01-09 08:32:24 +01:00
binfmt_elf: Respect error return from `regset->active'
2018-09-26 08:36:37 +02:00
fs/binfmt_flat.c: make load_flat_shared_library() work
2019-07-10 09:55:38 +02:00
fs/binfmt_misc.c: do not allow offset overflow
2018-06-26 08:08:09 +08:00
exec: load_script: Do not exec truncated interpreter path
2019-11-06 12:18:04 +01:00
blockdev: Fix livelocks on loop device
2019-01-23 08:10:56 +01:00
fs: fix guard_bio_eod to check for real EOD errors
2019-04-05 22:29:08 +02:00
chardev: Avoid potential use-after-free in 'chrdev_open()'
2020-01-14 20:04:25 +01:00
compat: remove compat_printk()
2016-09-27 21:20:53 -04:00
binfmt_elf: compat: avoid unused function warning
2018-02-25 11:05:55 +01:00
fix compat handling of FICLONERANGE, FIDEDUPERANGE and FS_IOC_FIEMAP
2020-01-12 11:24:17 +01:00
coredump: Ensure proper size of sparse core files
2017-07-05 14:40:26 +02:00
fs/dax.c: fix inefficiency in dax_writeback_mapping_range()
2018-02-28 10:18:33 +01:00
Hang/soft lockup in d_invalidate with simultaneous calls
2019-03-27 14:13:04 +09:00
direct-io: allow direct writes to empty inodes
2019-03-05 17:57:05 +01:00
fs/drop_caches.c: avoid softlockups in drop_pagecache_sb()
2019-03-13 14:04:58 -07:00
fs/epoll: drop ovflist branch prediction
2019-02-12 19:44:59 +01:00
sched/fair: Don't free p->numa_faults with concurrent readers
2019-08-04 09:33:45 +02:00
fs/fcntl: f_setown, avoid undefined behaviour
2018-01-31 12:55:52 +01:00
fs/file.c: initialize init_files.resize_wait
2019-04-05 22:29:07 +02:00
cgroup,writeback: don't switch wbs immediately on dead wbs if the memcg is dead
2019-11-12 19:16:11 +01:00
futex: Fix inode life-time issue
2020-04-02 17:20:27 +02:00
xfs: evict all inodes involved with log redo item
2017-09-20 08:20:01 +02:00
iomap: fix integer truncation issues in the zeroing and dirtying helpers
2017-09-20 08:19:59 +02:00
mm/hugetlb: introduce ARCH_HAS_GIGANTIC_PAGE
2016-10-07 18:46:29 -07:00
libfs: fix infoleak in simple_attr_read()
2020-04-02 17:20:38 +02:00
locks: print unsigned ino in /proc/locks
2020-01-12 11:24:13 +01:00
mbcache: initialize entry->e_referenced in mb_cache_entry_create()
2018-02-22 15:43:48 +01:00
mnt: In propgate_umount handle visiting mounts in any order
2017-07-21 07:42:22 +02:00
fs/mpage.c: fix mpage_writepage() for pages with buffers
2017-10-18 09:35:39 +02:00
namei: only return -ECHILD from follow_dotdot_rcu()
2020-03-11 07:53:07 +01:00
mount: Prevent MNT_DETACH from disconnecting locked mounts
2018-11-21 09:26:02 +01:00
nsfs: mark dentry with DCACHE_RCUACCESS
2018-02-17 13:21:15 +01:00
cifs_atomic_open(): fix double-put on late allocation failure
2020-03-20 09:07:44 +01:00
fs: prevent page refcount overflow in pipe_buf_get
2019-06-11 12:22:45 +02:00
mnt: Make propagate_umount less slow for overlapping mount propagation trees
2017-07-21 07:42:22 +02:00
mnt: Tuck mounts under others instead of creating shadow/side mounts.
2017-03-15 10:02:43 +08:00
tmpfs: clear S_ISGID when setting posix ACLs
2017-01-26 08:24:37 +01:00
fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock
2019-06-11 12:22:49 +02:00
filldir[64]: remove WARN_ON_ONCE() for bad directory entries
2020-01-04 13:41:06 +01:00
fs/select: add vmalloc fallback for select(2)
2016-10-11 15:06:30 -07:00
seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not char
2016-10-07 18:46:30 -07:00
fs: prevent page refcount overflow in pipe_buf_get
2019-06-11 12:22:45 +02:00
ufs: restore maintaining ->i_blocks
2017-06-14 15:06:01 +02:00
fs: don't scan the inode cache before SB_BORN is set
2019-02-06 17:33:29 +01:00
timerfd: Protect the might cancel mechanism proper
2017-05-08 07:47:54 +02:00
userfaultfd_release: always remove uffd flags and clear vm_userfaultfd_ctx
2019-09-06 10:19:37 +02:00
Merge remote-tracking branch 'jk/vfs' into work.misc
2016-10-08 11:06:08 -04:00
sysfs: Do not return POSIX ACL xattrs via listxattr
2018-10-10 08:53:22 +02:00
696119fa9f