No description
  • C 98.2%
  • Assembly 1%
  • Makefile 0.3%
  • Shell 0.2%
  • Python 0.1%
Find a file
Repository files (latest commit first)
Filename Latest commit message Latest commit date
NeilBrown b602345da6 nfsd: fix memory corruption caused by readdir
If the result of an NFSv3 readdir{,plus} request results in the
"offset" on one entry having to be split across 2 pages, and is sized
so that the next directory entry doesn't fit in the requested size,
then memory corruption can happen.

When encode_entry() is called after encoding the last entry that fits,
it notices that ->offset and ->offset1 are set, and so stores the
offset value in the two pages as required.  It clears ->offset1 but
*does not* clear ->offset.

Normally this omission doesn't matter as encode_entry_baggage() will
be called, and will set ->offset to a suitable value (not on a page
boundary).
But in the case where cd->buflen < elen and nfserr_toosmall is
returned, ->offset is not reset.

This means that nfsd3proc_readdirplus will see ->offset with a value 4
bytes before the end of a page, and ->offset1 set to NULL.
It will try to write 8bytes to ->offset.
If we are lucky, the next page will be read-only, and the system will
  BUG: unable to handle kernel paging request at...

If we are unlucky, some innocent page will have the first 4 bytes
corrupted.

nfsd3proc_readdir() doesn't even check for ->offset1, it just blindly
writes 8 bytes to the offset wherever it is.

Fix this by clearing ->offset after it is used, and copying the
->offset handling code from nfsd3_proc_readdirplus into
nfsd3_proc_readdir.

(Note that the commit hash in the Fixes tag is from the 'history'
 tree - this bug predates git).

Fixes: 0b1d57cf7654 ("[PATCH] kNFSd: Fix nfs3 dentry encoding")
Fixes-URL: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=0b1d57cf7654
Cc: stable@vger.kernel.org (v2.6.12+)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-03-05 16:41:33 -05:00
arch Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-02-03 09:08:12 -08:00
block blk-mq: fix a hung issue when fsync 2019-01-30 08:53:54 -07:00
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
Documentation Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-02-03 09:08:12 -08:00
drivers Merge branch 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-02-03 08:57:05 -08:00
firmware kbuild: change filechk to surround the given command with { } 2019-01-06 09:46:51 +09:00
fs nfsd: fix memory corruption caused by readdir 2019-03-05 16:41:33 -05:00
include Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-02-03 09:08:12 -08:00
init psi: clarify the Kconfig text for the default-disable option 2019-02-01 15:46:24 -08:00
ipc
kernel Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-02-03 09:02:03 -08:00
lib lib/test_kmod.c: potential double free in error handling 2019-02-01 15:46:23 -08:00
LICENSES
mm mm: migrate: don't rely on __PageMovable() of newpage after unlocking it 2019-02-01 15:46:24 -08:00
net svcrpc: fix UDP on servers with lots of threads 2019-02-21 10:17:36 -05:00
samples samples/bpf: workaround clang asm goto compilation errors 2019-01-15 20:57:30 +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-rc5 2019-01-31 10:00:00 -08:00
tools Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-02-03 08:59:51 -08:00
usr
virt KVM: validate userspace input in kvm_clear_dirty_log_protect() 2019-01-11 18:38:07 +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
.get_maintainer.ignore
.gitattributes
.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
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
MAINTAINERS Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-02-03 09:08:12 -08:00
Makefile Linux 5.0-rc5 2019-02-03 13:48:04 -08:00
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.