A mirror of the official Linux kernel repository just in case
Go to file
Dave Chinner 9e6c08d4a8 xfs: validate btree records on retrieval
So we don't check the validity of records as we walk the btree. When
there are corrupt records in the free space btree (e.g. zero
startblock/length or beyond EOAG) we just blindly use it and things
go bad from there. That leads to assert failures on debug kernels
like this:

XFS: Assertion failed: fs_is_ok, file: fs/xfs/libxfs/xfs_alloc.c, line: 450
....
Call Trace:
 xfs_alloc_fixup_trees+0x368/0x5c0
 xfs_alloc_ag_vextent_near+0x79a/0xe20
 xfs_alloc_ag_vextent+0x1d3/0x330
 xfs_alloc_vextent+0x5e9/0x870

Or crashes like this:

XFS (loop0): xfs_buf_find: daddr 0x7fb28 out of range, EOFS 0x8000
.....
BUG: unable to handle kernel NULL pointer dereference at 00000000000000c8
....
Call Trace:
 xfs_bmap_add_extent_hole_real+0x67d/0x930
 xfs_bmapi_write+0x934/0xc90
 xfs_da_grow_inode_int+0x27e/0x2f0
 xfs_dir2_grow_inode+0x55/0x130
 xfs_dir2_sf_to_block+0x94/0x5d0
 xfs_dir2_sf_addname+0xd0/0x590
 xfs_dir_createname+0x168/0x1a0
 xfs_rename+0x658/0x9b0

By checking that free space records pulled from the trees are
within the valid range, we catch many of these corruptions before
they can do damage.

This is a generic btree record checking deficiency. We need to
validate the records we fetch from all the different btrees before
we use them to catch corruptions like this.

This patch results in a corrupt record emitting an error message and
returning -EFSCORRUPTED, and the higher layers catch that and abort:

 XFS (loop0): Size Freespace BTree record corruption in AG 0 detected!
 XFS (loop0): start block 0x0 block count 0x0
 XFS (loop0): Internal error xfs_trans_cancel at line 1012 of file fs/xfs/xfs_trans.c.  Caller xfs_create+0x42a/0x670
 .....
 Call Trace:
  dump_stack+0x85/0xcb
  xfs_trans_cancel+0x19f/0x1c0
  xfs_create+0x42a/0x670
  xfs_generic_create+0x1f6/0x2c0
  vfs_create+0xf9/0x180
  do_mknodat+0x1f9/0x210
  do_syscall_64+0x5a/0x180
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
.....
 XFS (loop0): xfs_do_force_shutdown(0x8) called from line 1013 of file fs/xfs/xfs_trans.c.  Return address = ffffffff81500868
 XFS (loop0): Corruption of in-memory data detected.  Shutting down filesystem

Signed-off-by: Dave Chinner <dchinner@redhat.com>

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-06-06 08:12:00 -07:00
arch KVM fixes for v4.17-rc4 2018-05-06 05:46:29 -10:00
block block: add a lower-level bio_add_page interface 2018-06-01 18:37:32 -07:00
certs certs/blacklist_nohashes.c: fix const confusion in certs blacklist 2018-02-21 15:35:43 -08:00
crypto crypto: drbg - set freed buffers to NULL 2018-04-21 00:57:00 +08:00
Documentation fs: copy BTRFS_IOC_[SG]ET_FSLABEL to vfs 2018-05-16 08:50:16 -07:00
drivers dax: change bdev_dax_supported() to support boolean returns 2018-05-31 08:58:34 -07:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs xfs: validate btree records on retrieval 2018-06-06 08:12:00 -07:00
include fs: move page_cache_seek_hole_data to iomap.c 2018-06-01 18:37:33 -07:00
init Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-15 16:12:35 -07:00
ipc ipc/shm: fix use-after-free of shm file via remap_file_pages() 2018-04-13 17:10:27 -07:00
kernel Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-05-06 05:35:23 -10:00
lib swiotlb: fix inversed DMA_ATTR_NO_WARN test 2018-05-02 14:48:55 +02:00
LICENSES LICENSES: Add MPL-1.1 license 2018-01-06 10:59:44 -07:00
mm mm: split ->readpages calls to avoid non-contiguous pages lists 2018-06-01 18:37:32 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-05-03 18:57:03 -10:00
samples bpf: sockmap sample use clang flag, -target bpf 2018-04-23 23:42:21 +02:00
scripts Kbuild fixes for v4.17 2018-05-04 21:15:25 -10:00
security Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-04-24 17:58:51 -07:00
sound ALSA: pcm: Check PCM state at xfern compat ioctl 2018-05-02 08:54:54 +02:00
tools ACPI fix for 4.17-rc4 2018-05-04 05:43:33 -10:00
usr kbuild: rename built-in.o to built-in.a 2018-03-26 02:01:19 +09:00
virt KVM/arm fixes for 4.17, take #2 2018-05-05 23:05:31 +02:00
.clang-format clang-format: add configuration file 2018-04-11 10:28:35 -07:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap Merge candidates for 4.17 merge window 2018-04-06 17:35:43 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS/CREDITS: Drop METAG ARCHITECTURE 2018-03-05 16:34:24 +00:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS Kbuild fixes for v4.17 2018-05-04 21:15:25 -10:00
Makefile Linux 4.17-rc4 2018-05-06 16:57:38 -10:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -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.
See Documentation/00-INDEX for a list of what is contained in each file.

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.