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Darrick J. Wong 3b50086f0c xfs: don't overflow xattr listent buffer
For VFS listxattr calls, xfs_xattr_put_listent calls
__xfs_xattr_put_listent twice if it sees an attribute
"trusted.SGI_ACL_FILE": once for that name, and again for
"system.posix_acl_access".  Unfortunately, if we happen to run out of
buffer space while emitting the first name, we set count to -1 (so that
we can feed ERANGE to the caller).  The second invocation doesn't check that
the context parameters make sense and overwrites the byte before the
buffer, triggering a KASAN report:

==================================================================
BUG: KASAN: slab-out-of-bounds in strncpy+0xb3/0xd0
Write of size 1 at addr ffff88807fbd317f by task syz/1113

CPU: 3 PID: 1113 Comm: syz Not tainted 5.0.0-rc6-xfsx #rc6
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
 dump_stack+0xcc/0x180
 print_address_description+0x6c/0x23c
 kasan_report.cold.3+0x1c/0x35
 strncpy+0xb3/0xd0
 __xfs_xattr_put_listent+0x1a9/0x2c0 [xfs]
 xfs_attr_list_int_ilocked+0x11af/0x1800 [xfs]
 xfs_attr_list_int+0x20c/0x2e0 [xfs]
 xfs_vn_listxattr+0x225/0x320 [xfs]
 listxattr+0x11f/0x1b0
 path_listxattr+0xbd/0x130
 do_syscall_64+0x139/0x560

While we're at it we add an assert to the other put_listent to avoid
this sort of thing ever happening to the attrlist_by_handle code.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2019-02-14 09:36:52 -08:00
Documentation xfs: Introduce XFS_PTAG_VERIFIER_ERROR panic mask 2019-02-11 16:07:00 -08:00
LICENSES This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
arch Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-02-10 09:57:42 -08:00
block for-linus-20190209 2019-02-09 10:26:09 -08:00
certs kbuild: remove redundant target cleaning on failure 2019-01-06 09:46:51 +09:00
crypto crypto: sm3 - fix undefined shift by >= width of value 2019-01-10 21:37:32 +08:00
drivers dmaengine-fix-5.0-rc6 2019-02-10 10:39:37 -08:00
firmware kbuild: change filechk to surround the given command with { } 2019-01-06 09:46:51 +09:00
fs xfs: don't overflow xattr listent buffer 2019-02-14 09:36:52 -08:00
include Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-02-10 09:54:19 -08:00
init psi: clarify the Kconfig text for the default-disable option 2019-02-01 15:46:24 -08:00
ipc ipc: IPCMNI limit check for semmni 2018-10-31 08:54:14 -07:00
kernel Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-02-10 09:48:18 -08:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-02-08 11:21:54 -08:00
mm mm: migrate: don't rely on __PageMovable() of newpage after unlocking it 2019-02-01 15:46:24 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-02-08 11:21:54 -08:00
samples samples: mei: use /dev/mei0 instead of /dev/mei 2019-01-30 15:24:45 +01:00
scripts Bug fixes for gcc-plugins 2019-01-21 13:07:03 +13:00
security apparmor: Fix aa_label_build() error handling for failed merges 2019-02-01 08:01:39 -08:00
sound sound fixes for 5.0-rc6 2019-02-07 08:33:56 +00:00
tools Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-02-10 09:48:18 -08:00
usr user/Makefile: Fix typo and capitalization in comment section 2018-12-11 00:18:03 +09:00
virt kvm: fix kvm_ioctl_create_device() reference counting (CVE-2019-6974) 2019-02-07 19:02:38 +01:00
.clang-format clang-format: Update .clang-format with the latest for_each macro list 2019-01-19 19:26:06 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support for DT binding schema checks 2018-12-13 09:41:32 -06:00
.mailmap A few early MIPS fixes for 4.21: 2019-01-05 12:48:25 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Add CREDITS entry for Shaohua Li 2019-01-04 14:27:09 -07:00
Kbuild kbuild: use assignment instead of define ... endef for filechk_* rules 2019-01-06 10:22:35 +09:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2019-02-09 13:43:12 -08:00
Makefile Linux 5.0-rc6 2019-02-10 14:42:20 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

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.