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Filipe Manana b3317a799f btrfs: fix a block group ref counter leak after failure to remove block group
[ Upstream commit 9fecd13202 ]

When removing a block group, if we fail to delete the block group's item
from the extent tree, we jump to the 'out' label and end up decrementing
the block group's reference count once only (by 1), resulting in a counter
leak because the block group at that point was already removed from the
block group cache rbtree - so we have to decrement the reference count
twice, once for the rbtree and once for our lookup at the start of the
function.

There is a second bug where if removing the free space tree entries (the
call to remove_block_group_free_space()) fails we end up jumping to the
'out_put_group' label but end up decrementing the reference count only
once, when we should have done it twice, since we have already removed
the block group from the block group cache rbtree. This happens because
the reference count decrement for the rbtree reference happens after
attempting to remove the free space tree entries, which is far away from
the place where we remove the block group from the rbtree.

To make things less error prone, decrement the reference count for the
rbtree immediately after removing the block group from it. This also
eleminates the need for two different exit labels on error, renaming
'out_put_label' to just 'out' and removing the old 'out'.

Fixes: f6033c5e33 ("btrfs: fix block group leak when removing fails")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-07-09 09:37:08 +02:00
arch arm64: perf: Report the PC value in REGS_ABI_32 mode 2020-06-30 23:17:17 -04:00
block block/bio-integrity: don't free 'buf' if bio_integrity_add_page() failed 2020-06-30 23:17:00 -04:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto crypto: algboss - don't wait during notifier callback 2020-06-25 15:33:09 +02:00
Documentation mtd: rawnand: Pass a nand_chip object to nand_release() 2020-06-25 15:33:08 +02:00
drivers Revert "tty: hvc: Fix data abort due to race in hvc_open" 2020-06-30 23:17:19 -04:00
firmware Fix built-in early-load Intel microcode alignment 2020-01-23 08:21:29 +01:00
fs btrfs: fix a block group ref counter leak after failure to remove block group 2020-07-09 09:37:08 +02:00
include net: qed: fix left elements count calculation 2020-06-30 23:17:12 -04:00
init x86: Fix early boot crash on gcc-10, third try 2020-05-20 08:18:49 +02:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2020-05-20 08:18:40 +02:00
kernel ring-buffer: Zero out time extend if it is nested and not absolute 2020-06-30 23:17:17 -04:00
lib lib/zlib: remove outdated and incorrect pre-increment optimization 2020-06-25 15:33:02 +02:00
LICENSES LICENSES: Remove CC-BY-SA-4.0 license text 2018-10-18 11:28:50 +02:00
mm mm/slab: use memzero_explicit() in kzfree() 2020-06-30 23:17:16 -04:00
net SUNRPC: Properly set the @subbuf parameter of xdr_buf_subsegment() 2020-06-30 23:17:18 -04:00
samples samples: bpf: Fix build error 2020-06-03 08:19:31 +02:00
scripts kbuild: improve cc-option to clean up all temporary files 2020-06-30 23:17:15 -04:00
security apparmor: don't try to replace stale label in ptraceme check 2020-06-30 23:17:03 -04:00
sound ALSA: hda/realtek - Add quirk for MSI GE63 laptop 2020-06-30 23:17:15 -04:00
tools perf report: Fix NULL pointer dereference in hists__fprintf_nr_sample_events() 2020-06-25 15:33:05 +02:00
usr initramfs: restore default compression behavior 2020-04-13 10:44:59 +02:00
virt KVM: arm64: Synchronize sysreg state on injecting an AArch32 exception 2020-06-22 09:05:09 +02:00
.clang-format clang-format: Set IndentWrappedFunctionNames false 2018-08-01 18:38:51 +02:00
.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 libnvdimm-for-4.19_misc 2018-08-25 18:13:10 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS 9p: remove Ron Minnich from MAINTAINERS 2018-08-17 16:20:26 -07:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS MAINTAINERS: Update drm/i915 bug filing URL 2020-02-28 16:38:49 +01:00
Makefile Linux 4.19.131 2020-06-30 23:20:17 -04:00
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.