linux/fs/hfsplus
Ernesto A. Fernández a7ec7a4193 hfsplus: fix NULL dereference in hfsplus_lookup()
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>
2018-08-23 18:48:42 -07:00
..
attributes.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
bfind.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
bitmap.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
bnode.c hfs/hfsplus: clean up unused variables in bnode.c 2017-11-17 16:10:03 -08:00
brec.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
btree.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
catalog.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dir.c hfsplus: fix NULL dereference in hfsplus_lookup() 2018-08-23 18:48:42 -07:00
extents.c hfsplus: avoid deadlock on file truncation 2018-08-22 10:52:50 -07:00
hfsplus_fs.h hfsplus: drop ACL support 2018-08-22 10:52:50 -07:00
hfsplus_raw.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
inode.c hfsplus: drop ACL support 2018-08-22 10:52:50 -07:00
ioctl.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig hfsplus: drop ACL support 2018-08-22 10:52:50 -07:00
Makefile hfsplus: drop ACL support 2018-08-22 10:52:50 -07:00
options.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
part_tbl.c hfsplus: use bio op accessors 2016-06-07 13:41:38 -06:00
super.c hfsplus: drop ACL support 2018-08-22 10:52:50 -07:00
tables.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
unicode.c hfsplus: fix decomposition of Hangul characters 2018-08-22 10:52:50 -07:00
wrapper.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xattr_security.c hfsplus: drop ACL support 2018-08-22 10:52:50 -07:00
xattr_trusted.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xattr_user.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xattr.c hfsplus: drop ACL support 2018-08-22 10:52:50 -07:00
xattr.h hfsplus: drop ACL support 2018-08-22 10:52:50 -07:00