android_kernel_oneplus_msm8998/fs/hfsplus
Ernesto A. Fernández fed5bd3352 hfsplus: fix NULL dereference in hfsplus_lookup()
[ Upstream commit a7ec7a4193a2eb3b5341243fc0b621c1ac9e4ec4 ]

An HFS+ filesystem can be mounted read-only without having a metadata
directory, which is needed to support hardlinks.  But if the catalog
data is corrupted, a directory lookup may still find dentries claiming
to be hardlinks.

hfsplus_lookup() does check that ->hidden_dir is not NULL in such a
situation, but mistakenly does so after dereferencing it for the first
time.  Reorder this check to prevent a crash.

This happens when looking up corrupted catalog data (dentry) on a
filesystem with no metadata directory (this could only ever happen on a
read-only mount).  Wen Xu sent the replication steps in detail to the
fsdevel list: https://bugzilla.kernel.org/show_bug.cgi?id=200297

Link: http://lkml.kernel.org/r/20180712215344.q44dyrhymm4ajkao@eaf
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Reported-by: Wen Xu <wen.xu@gatech.edu>
Cc: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-15 09:40:38 +02:00
..
acl.h
attributes.c
bfind.c
bitmap.c
bnode.c
brec.c
btree.c
catalog.c
dir.c hfsplus: fix NULL dereference in hfsplus_lookup() 2018-09-15 09:40:38 +02:00
extents.c
hfsplus_fs.h
hfsplus_raw.h
inode.c
ioctl.c
Kconfig
Makefile
options.c
part_tbl.c
posix_acl.c
super.c
tables.c
unicode.c
wrapper.c
xattr.c
xattr.h
xattr_security.c
xattr_trusted.c
xattr_user.c