Linux kernel source tree
Go to file
Ye Bin 298b5c5217 ext4: fix null-ptr-deref in '__ext4_journal_ensure_credits'
We got issue as follows when run syzkaller test:
[ 1901.130043] EXT4-fs error (device vda): ext4_remount:5624: comm syz-executor.5: Abort forced by user
[ 1901.130901] Aborting journal on device vda-8.
[ 1901.131437] EXT4-fs error (device vda): ext4_journal_check_start:61: comm syz-executor.16: Detected aborted journal
[ 1901.131566] EXT4-fs error (device vda): ext4_journal_check_start:61: comm syz-executor.11: Detected aborted journal
[ 1901.132586] EXT4-fs error (device vda): ext4_journal_check_start:61: comm syz-executor.18: Detected aborted journal
[ 1901.132751] EXT4-fs error (device vda): ext4_journal_check_start:61: comm syz-executor.9: Detected aborted journal
[ 1901.136149] EXT4-fs error (device vda) in ext4_reserve_inode_write:6035: Journal has aborted
[ 1901.136837] EXT4-fs error (device vda): ext4_journal_check_start:61: comm syz-fuzzer: Detected aborted journal
[ 1901.136915] ==================================================================
[ 1901.138175] BUG: KASAN: null-ptr-deref in __ext4_journal_ensure_credits+0x74/0x140 [ext4]
[ 1901.138343] EXT4-fs error (device vda): ext4_journal_check_start:61: comm syz-executor.13: Detected aborted journal
[ 1901.138398] EXT4-fs error (device vda): ext4_journal_check_start:61: comm syz-executor.1: Detected aborted journal
[ 1901.138808] Read of size 8 at addr 0000000000000000 by task syz-executor.17/968
[ 1901.138817]
[ 1901.138852] EXT4-fs error (device vda): ext4_journal_check_start:61: comm syz-executor.30: Detected aborted journal
[ 1901.144779] CPU: 1 PID: 968 Comm: syz-executor.17 Not tainted 4.19.90-vhulk2111.1.0.h893.eulerosv2r10.aarch64+ #1
[ 1901.146479] Hardware name: linux,dummy-virt (DT)
[ 1901.147317] Call trace:
[ 1901.147552]  dump_backtrace+0x0/0x2d8
[ 1901.147898]  show_stack+0x28/0x38
[ 1901.148215]  dump_stack+0xec/0x15c
[ 1901.148746]  kasan_report+0x108/0x338
[ 1901.149207]  __asan_load8+0x58/0xb0
[ 1901.149753]  __ext4_journal_ensure_credits+0x74/0x140 [ext4]
[ 1901.150579]  ext4_xattr_delete_inode+0xe4/0x700 [ext4]
[ 1901.151316]  ext4_evict_inode+0x524/0xba8 [ext4]
[ 1901.151985]  evict+0x1a4/0x378
[ 1901.152353]  iput+0x310/0x428
[ 1901.152733]  do_unlinkat+0x260/0x428
[ 1901.153056]  __arm64_sys_unlinkat+0x6c/0xc0
[ 1901.153455]  el0_svc_common+0xc8/0x320
[ 1901.153799]  el0_svc_handler+0xf8/0x160
[ 1901.154265]  el0_svc+0x10/0x218
[ 1901.154682] ==================================================================

This issue may happens like this:
	Process1                               Process2
ext4_evict_inode
  ext4_journal_start
   ext4_truncate
     ext4_ind_truncate
       ext4_free_branches
         ext4_ind_truncate_ensure_credits
	   ext4_journal_ensure_credits_fn
	     ext4_journal_restart
	       handle->h_transaction = NULL;
                                           mount -o remount,abort  /mnt
					   -> trigger JBD abort
               start_this_handle -> will return failed
  ext4_xattr_delete_inode
    ext4_journal_ensure_credits
      ext4_journal_ensure_credits_fn
        __ext4_journal_ensure_credits
	  jbd2_handle_buffer_credits
	    journal = handle->h_transaction->t_journal; ->null-ptr-deref

Now, indirect truncate process didn't handle error. To solve this issue
maybe simply add check handle is abort in '__ext4_journal_ensure_credits'
is enough, and i also think this is necessary.

Cc: stable@kernel.org
Signed-off-by: Ye Bin <yebin10@huawei.com>
Link: https://lore.kernel.org/r/20211224100341.3299128-1-yebin10@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-01-10 13:25:55 -05:00
arch parisc architecture bug and warning fixes for kernel v5.16-rc4 2021-12-05 12:58:18 -08:00
block block: call rq_qos_done() before ref check in batch completions 2021-11-26 09:53:23 -07:00
certs certs: Add support for using elliptic curve keys for signing modules 2021-08-23 19:55:42 +03:00
crypto Update to zstd-1.4.10 2021-11-13 15:32:30 -08:00
Documentation Power management fixes for 5.16-rc4 2021-12-03 12:22:56 -08:00
drivers parisc architecture bug and warning fixes for kernel v5.16-rc4 2021-12-05 12:58:18 -08:00
fs ext4: fix null-ptr-deref in '__ext4_journal_ensure_credits' 2022-01-10 13:25:55 -05:00
include fs_parse: allow parameter value to be empty 2021-12-09 14:09:36 -05:00
init kbuild: Fix -Wimplicit-fallthrough=5 error for GCC 5.x and 6.x 2021-11-14 18:59:49 -08:00
ipc shm: extend forced shm destroy to support objects from several IPC nses 2021-11-20 10:35:54 -08:00
kernel - Prevent a tick storm when a dedicated timekeeper CPU in nohz_full 2021-12-05 08:58:52 -08:00
lib siphash: use _unaligned version by default 2021-11-29 19:50:50 -08:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm Fixes for 5.16 folios: 2021-11-25 10:13:56 -08:00
net Networking fixes for 5.16-rc4, including fixes from wireless, 2021-12-02 11:22:06 -08:00
samples s390 updates for 5.16-rc2 2021-11-20 10:55:50 -08:00
scripts Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid 2021-11-24 09:44:13 -08:00
security selinux: fix NULL-pointer dereference when hashtab allocation fails 2021-11-19 16:11:39 -05:00
sound sound fixes for 5.16-rc4 2021-12-01 10:07:39 -08:00
tools - Fix a couple of SWAPGS fencing issues in the x86 entry code 2021-12-05 08:43:35 -08:00
usr initramfs: Check timestamp to prevent broken cpio archive 2021-10-24 13:48:40 +09:00
virt KVM: downgrade two BUG_ONs to WARN_ON_ONCE 2021-11-26 06:43:28 -05:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap MAINTAINERS: update email address of Christian Borntraeger 2021-11-18 17:50:54 +01:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS TTY/Serial fixes for 5.16-rc4 2021-12-05 09:13:20 -08:00
Makefile Linux 5.16-rc4 2021-12-05 14:08:22 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.