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Luís Henriques 29a5b8a137 ext4: fix bug in extents parsing when eh_entries == 0 and eh_depth > 0
When walking through an inode extents, the ext4_ext_binsearch_idx() function
assumes that the extent header has been previously validated.  However, there
are no checks that verify that the number of entries (eh->eh_entries) is
non-zero when depth is > 0.  And this will lead to problems because the
EXT_FIRST_INDEX() and EXT_LAST_INDEX() will return garbage and result in this:

[  135.245946] ------------[ cut here ]------------
[  135.247579] kernel BUG at fs/ext4/extents.c:2258!
[  135.249045] invalid opcode: 0000 [#1] PREEMPT SMP
[  135.250320] CPU: 2 PID: 238 Comm: tmp118 Not tainted 5.19.0-rc8+ #4
[  135.252067] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014
[  135.255065] RIP: 0010:ext4_ext_map_blocks+0xc20/0xcb0
[  135.256475] Code:
[  135.261433] RSP: 0018:ffffc900005939f8 EFLAGS: 00010246
[  135.262847] RAX: 0000000000000024 RBX: ffffc90000593b70 RCX: 0000000000000023
[  135.264765] RDX: ffff8880038e5f10 RSI: 0000000000000003 RDI: ffff8880046e922c
[  135.266670] RBP: ffff8880046e9348 R08: 0000000000000001 R09: ffff888002ca580c
[  135.268576] R10: 0000000000002602 R11: 0000000000000000 R12: 0000000000000024
[  135.270477] R13: 0000000000000000 R14: 0000000000000024 R15: 0000000000000000
[  135.272394] FS:  00007fdabdc56740(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000
[  135.274510] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  135.276075] CR2: 00007ffc26bd4f00 CR3: 0000000006261004 CR4: 0000000000170ea0
[  135.277952] Call Trace:
[  135.278635]  <TASK>
[  135.279247]  ? preempt_count_add+0x6d/0xa0
[  135.280358]  ? percpu_counter_add_batch+0x55/0xb0
[  135.281612]  ? _raw_read_unlock+0x18/0x30
[  135.282704]  ext4_map_blocks+0x294/0x5a0
[  135.283745]  ? xa_load+0x6f/0xa0
[  135.284562]  ext4_mpage_readpages+0x3d6/0x770
[  135.285646]  read_pages+0x67/0x1d0
[  135.286492]  ? folio_add_lru+0x51/0x80
[  135.287441]  page_cache_ra_unbounded+0x124/0x170
[  135.288510]  filemap_get_pages+0x23d/0x5a0
[  135.289457]  ? path_openat+0xa72/0xdd0
[  135.290332]  filemap_read+0xbf/0x300
[  135.291158]  ? _raw_spin_lock_irqsave+0x17/0x40
[  135.292192]  new_sync_read+0x103/0x170
[  135.293014]  vfs_read+0x15d/0x180
[  135.293745]  ksys_read+0xa1/0xe0
[  135.294461]  do_syscall_64+0x3c/0x80
[  135.295284]  entry_SYSCALL_64_after_hwframe+0x46/0xb0

This patch simply adds an extra check in __ext4_ext_check(), verifying that
eh_entries is not 0 when eh_depth is > 0.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=215941
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216283
Cc: Baokun Li <libaokun1@huawei.com>
Cc: stable@kernel.org
Signed-off-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Link: https://lore.kernel.org/r/20220822094235.2690-1-lhenriques@suse.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-09-22 10:50:54 -04:00
arch powerpc fixes for 6.0 #4 2022-09-04 11:33:22 -07:00
block block-6.0-2022-08-26 2022-08-26 11:05:54 -07:00
certs Kbuild updates for v5.20 2022-08-10 10:40:41 -07:00
crypto crypto: blake2b: effectively disable frame size warning 2022-08-10 17:59:11 -07:00
Documentation Input updates for v6.0-rc3 2022-09-03 13:09:46 -07:00
drivers s390: 2022-09-04 11:27:14 -07:00
fs ext4: fix bug in extents parsing when eh_entries == 0 and eh_depth > 0 2022-09-22 10:50:54 -04:00
include TTY/Serial driver fixes for 6.0-rc4 2022-09-03 10:34:02 -07:00
init arm64 fixes for -rc3 2022-08-26 11:32:53 -07:00
io_uring io_uring-6.0-2022-09-02 2022-09-02 16:37:01 -07:00
ipc Updates to various subsystems which I help look after. lib, ocfs2, 2022-08-07 10:03:24 -07:00
kernel Networking fixes for 6.0-rc4, including fixes from bluetooth, bpf 2022-09-01 09:20:42 -07:00
lib This push fixes a boot performance regression due to an unnecessary 2022-08-31 09:47:06 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm: pagewalk: Fix race between unmap and page walker 2022-09-03 10:13:13 -07:00
net net/smc: Remove redundant refcount increase 2022-09-01 10:04:45 +02:00
samples Tracing updates for 5.20 / 6.0 2022-08-05 09:41:12 -07:00
scripts Makefile.extrawarn: re-enable -Wformat for clang; take 2 2022-09-04 11:15:50 -07:00
security Landlock fix for v6.0-rc4 2022-09-02 15:24:08 -07:00
sound ALSA: usb-audio: Add quirk for LH Labs Geek Out HD Audio 1V5 2022-08-28 09:42:14 +02:00
tools s390: 2022-09-04 11:27:14 -07:00
usr Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
virt KVM: Drop unnecessary initialization of "ops" in kvm_ioctl_create_device() 2022-08-19 04:05:43 -04:00
.clang-format PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: split the second line of *.mod into *.usyms 2022-05-08 03:16:59 +09:00
.mailmap .mailmap: update Luca Ceresoli's e-mail address 2022-08-28 14:02:46 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS drm for 5.20/6.0 2022-08-03 19:52:08 -07:00
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 gpio fixes for v6.0-rc4 2022-09-03 21:27:27 -07:00
Makefile Linux 6.0-rc4 2022-09-04 13:10:01 -07:00
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.