This is the start of the stable review cycle for the 6.6.75 release.
There are 43 patches in this series, all will be posted as a response
to this one. If anyone has any issues with these being applied, please
let me know.
Responses should be made by Sat, 01 Feb 2025 13:34:42 +0000.
Anything received after that time might be too late.
The whole patch series can be found in one patch at:
https://www.kernel.org/pub/linux/kernel/v6.x/stable-review/patch-6.6.75-rc1…
or in the git tree and branch at:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-6.6.y
and the diffstat can be found below.
thanks,
greg k-h
-------------
Pseudo-Shortlog of commits:
Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Linux 6.6.75-rc1
Jack Greiner <jack(a)emoss.org>
Input: xpad - add support for wooting two he (arm)
Matheos Mattsson <matheos.mattsson(a)gmail.com>
Input: xpad - add support for Nacon Evol-X Xbox One Controller
Leonardo Brondani Schenkel <leonardo(a)schenkel.net>
Input: xpad - improve name of 8BitDo controller 2dc8:3106
Pierre-Loup A. Griffais <pgriffais(a)valvesoftware.com>
Input: xpad - add QH Electronics VID/PID
Nilton Perim Neto <niltonperimneto(a)gmail.com>
Input: xpad - add unofficial Xbox 360 wireless receiver clone
Mark Pearson <mpearson-lenovo(a)squebb.ca>
Input: atkbd - map F23 key to support default copilot shortcut
Nicolas Nobelis <nicolas(a)nobelis.eu>
Input: xpad - add support for Nacon Pro Compact
Lianqin Hu <hulianqin(a)vivo.com>
ALSA: usb-audio: Add delay quirk for USB Audio Device
Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Revert "usb: gadget: u_serial: Disable ep before setting port to null to fix the crash caused by port being null"
Qasim Ijaz <qasdev00(a)gmail.com>
USB: serial: quatech2: fix null-ptr-deref in qt2_process_read_urb()
Easwar Hariharan <eahariha(a)linux.microsoft.com>
scsi: storvsc: Ratelimit warning logs to prevent VM denial of service
Ido Schimmel <idosch(a)nvidia.com>
ipv4: ip_tunnel: Fix suspicious RCU usage warning in ip_tunnel_find()
Luis Henriques (SUSE) <luis.henriques(a)linux.dev>
ext4: fix access to uninitialised lock in fc replay path
Alex Williamson <alex.williamson(a)redhat.com>
vfio/platform: check the bounds of read/write syscalls
Linus Torvalds <torvalds(a)linux-foundation.org>
cachestat: fix page cache statistics permission checking
Jiri Kosina <jkosina(a)suse.com>
Revert "HID: multitouch: Add support for lenovo Y9000P Touchpad"
Alexey Dobriyan <adobriyan(a)gmail.com>
block: fix integer overflow in BLKSECDISCARD
Jamal Hadi Salim <jhs(a)mojatatu.com>
net: sched: fix ets qdisc OOB Indexing
Paulo Alcantara <pc(a)manguebit.com>
smb: client: handle lack of EA support in smb2_query_path_info()
Chuck Lever <chuck.lever(a)oracle.com>
libfs: Use d_children list to iterate simple_offset directories
Chuck Lever <chuck.lever(a)oracle.com>
libfs: Replace simple_offset end-of-directory detection
Chuck Lever <chuck.lever(a)oracle.com>
Revert "libfs: Add simple_offset_empty()"
Chuck Lever <chuck.lever(a)oracle.com>
libfs: Return ENOSPC when the directory offset range is exhausted
Chuck Lever <chuck.lever(a)oracle.com>
shmem: Fix shmem_rename2()
Chuck Lever <chuck.lever(a)oracle.com>
libfs: Add simple_offset_rename() API
Chuck Lever <chuck.lever(a)oracle.com>
libfs: Fix simple_offset_rename_exchange()
Chuck Lever <chuck.lever(a)oracle.com>
libfs: Add simple_offset_empty()
Chuck Lever <chuck.lever(a)oracle.com>
libfs: Define a minimum directory offset
Chuck Lever <chuck.lever(a)oracle.com>
libfs: Re-arrange locking in offset_iterate_dir()
Andreas Gruenbacher <agruenba(a)redhat.com>
gfs2: Truncate address space when flipping GFS2_DIF_JDATA flag
Selvin Xavier <selvin.xavier(a)broadcom.com>
RDMA/bnxt_re: Avoid CPU lockups due fifo occupancy check loop
Omid Ehtemam-Haghighi <omid.ehtemamhaghighi(a)menlosecurity.com>
ipv6: Fix soft lockups in fib6_select_path under high next hop churn
Anastasia Belova <abelova(a)astralinux.ru>
cpufreq: amd-pstate: add check for cpufreq_cpu_get's return value
Igor Pylypiv <ipylypiv(a)google.com>
ata: libata-core: Set ATA_QCFLAG_RTF_FILLED in fill_result_tf()
Charles Keepax <ckeepax(a)opensource.cirrus.com>
ASoC: samsung: Add missing depends on I2C
Russell Harmon <russ(a)har.mn>
hwmon: (drivetemp) Set scsi command timeout to 10s
Philippe Simons <simons.philippe(a)gmail.com>
irqchip/sunxi-nmi: Add missing SKIP_WAKE flag
Rob Herring (Arm) <robh(a)kernel.org>
of/unittest: Add test that of_address_to_resource() fails on non-translatable address
Tom Chung <chiahsuan.chung(a)amd.com>
drm/amd/display: Use HW lock mgr for PSR1
Xiang Zhang <hawkxiang.cpp(a)gmail.com>
scsi: iscsi: Fix redundant response for ISCSI_UEVENT_GET_HOST_STATS request
Linus Walleij <linus.walleij(a)linaro.org>
seccomp: Stub for !CONFIG_SECCOMP
Charles Keepax <ckeepax(a)opensource.cirrus.com>
ASoC: samsung: Add missing selects for MFD_WM8994
Charles Keepax <ckeepax(a)opensource.cirrus.com>
ASoC: wm8994: Add depends on MFD core
-------------
Diffstat:
Makefile | 4 +-
block/ioctl.c | 9 +-
drivers/ata/libahci.c | 12 +-
drivers/ata/libata-core.c | 8 +
drivers/cpufreq/amd-pstate.c | 7 +-
.../gpu/drm/amd/display/dc/dce/dmub_hw_lock_mgr.c | 3 +-
drivers/hid/hid-ids.h | 1 -
drivers/hid/hid-multitouch.c | 8 +-
drivers/hwmon/drivetemp.c | 2 +-
drivers/infiniband/hw/bnxt_re/main.c | 10 +
drivers/input/joystick/xpad.c | 9 +-
drivers/input/keyboard/atkbd.c | 2 +-
drivers/irqchip/irq-sunxi-nmi.c | 3 +-
drivers/of/unittest-data/tests-platform.dtsi | 13 +
drivers/of/unittest.c | 14 ++
drivers/scsi/scsi_transport_iscsi.c | 4 +-
drivers/scsi/storvsc_drv.c | 8 +-
drivers/usb/gadget/function/u_serial.c | 8 +-
drivers/usb/serial/quatech2.c | 2 +-
drivers/vfio/platform/vfio_platform_common.c | 10 +
fs/ext4/super.c | 3 +-
fs/gfs2/file.c | 1 +
fs/libfs.c | 177 ++++++++++----
fs/smb/client/smb2inode.c | 104 +++++---
include/linux/fs.h | 2 +
include/linux/seccomp.h | 2 +-
mm/filemap.c | 19 ++
mm/shmem.c | 3 +-
net/ipv4/ip_tunnel.c | 2 +-
net/ipv6/ip6_fib.c | 8 +-
net/ipv6/route.c | 45 ++--
net/sched/sch_ets.c | 2 +
sound/soc/codecs/Kconfig | 1 +
sound/soc/samsung/Kconfig | 6 +-
sound/usb/quirks.c | 2 +
tools/testing/selftests/net/Makefile | 1 +
.../selftests/net/ipv6_route_update_soft_lockup.sh | 262 +++++++++++++++++++++
37 files changed, 640 insertions(+), 137 deletions(-)
This is the start of the stable review cycle for the 6.12.12 release.
There are 41 patches in this series, all will be posted as a response
to this one. If anyone has any issues with these being applied, please
let me know.
Responses should be made by Sat, 01 Feb 2025 14:41:19 +0000.
Anything received after that time might be too late.
The whole patch series can be found in one patch at:
https://www.kernel.org/pub/linux/kernel/v6.x/stable-review/patch-6.12.12-rc…
or in the git tree and branch at:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-6.12.y
and the diffstat can be found below.
thanks,
greg k-h
-------------
Pseudo-Shortlog of commits:
Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Linux 6.12.12-rc2
Jann Horn <jannh(a)google.com>
io_uring/rsrc: require cloned buffers to share accounting contexts
Jack Greiner <jack(a)emoss.org>
Input: xpad - add support for wooting two he (arm)
Matheos Mattsson <matheos.mattsson(a)gmail.com>
Input: xpad - add support for Nacon Evol-X Xbox One Controller
Leonardo Brondani Schenkel <leonardo(a)schenkel.net>
Input: xpad - improve name of 8BitDo controller 2dc8:3106
Pierre-Loup A. Griffais <pgriffais(a)valvesoftware.com>
Input: xpad - add QH Electronics VID/PID
Nilton Perim Neto <niltonperimneto(a)gmail.com>
Input: xpad - add unofficial Xbox 360 wireless receiver clone
Mark Pearson <mpearson-lenovo(a)squebb.ca>
Input: atkbd - map F23 key to support default copilot shortcut
Nicolas Nobelis <nicolas(a)nobelis.eu>
Input: xpad - add support for Nacon Pro Compact
Jason Gerecke <jason.gerecke(a)wacom.com>
HID: wacom: Initialize brightness of LED trigger
Hans de Goede <hdegoede(a)redhat.com>
wifi: rtl8xxxu: add more missing rtl8192cu USB IDs
Lianqin Hu <hulianqin(a)vivo.com>
ALSA: usb-audio: Add delay quirk for USB Audio Device
Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Revert "usb: gadget: u_serial: Disable ep before setting port to null to fix the crash caused by port being null"
Qasim Ijaz <qasdev00(a)gmail.com>
USB: serial: quatech2: fix null-ptr-deref in qt2_process_read_urb()
Easwar Hariharan <eahariha(a)linux.microsoft.com>
scsi: storvsc: Ratelimit warning logs to prevent VM denial of service
Alex Williamson <alex.williamson(a)redhat.com>
vfio/platform: check the bounds of read/write syscalls
Linus Torvalds <torvalds(a)linux-foundation.org>
cachestat: fix page cache statistics permission checking
Jiri Kosina <jikos(a)kernel.org>
Revert "HID: multitouch: Add support for lenovo Y9000P Touchpad"
Jamal Hadi Salim <jhs(a)mojatatu.com>
net: sched: fix ets qdisc OOB Indexing
Paulo Alcantara <pc(a)manguebit.com>
smb: client: handle lack of EA support in smb2_query_path_info()
Chuck Lever <chuck.lever(a)oracle.com>
libfs: Use d_children list to iterate simple_offset directories
Chuck Lever <chuck.lever(a)oracle.com>
libfs: Replace simple_offset end-of-directory detection
Chuck Lever <chuck.lever(a)oracle.com>
Revert "libfs: fix infinite directory reads for offset dir"
Chuck Lever <chuck.lever(a)oracle.com>
Revert "libfs: Add simple_offset_empty()"
Chuck Lever <chuck.lever(a)oracle.com>
libfs: Return ENOSPC when the directory offset range is exhausted
Andreas Gruenbacher <agruenba(a)redhat.com>
gfs2: Truncate address space when flipping GFS2_DIF_JDATA flag
Yosry Ahmed <yosryahmed(a)google.com>
mm: zswap: move allocations during CPU init outside the lock
Yosry Ahmed <yosryahmed(a)google.com>
mm: zswap: properly synchronize freeing resources during CPU hotunplug
Charles Keepax <ckeepax(a)opensource.cirrus.com>
ASoC: samsung: Add missing depends on I2C
Russell Harmon <russ(a)har.mn>
hwmon: (drivetemp) Set scsi command timeout to 10s
Philippe Simons <simons.philippe(a)gmail.com>
irqchip/sunxi-nmi: Add missing SKIP_WAKE flag
Cristian Ciocaltea <cristian.ciocaltea(a)collabora.com>
drm/connector: hdmi: Validate supported_formats matches ycbcr_420_allowed
Yage Geng <icoderdev(a)gmail.com>
ALSA: hda/realtek: Fix volume adjustment issue on Lenovo ThinkBook 16P Gen5
Rob Herring (Arm) <robh(a)kernel.org>
of/unittest: Add test that of_address_to_resource() fails on non-translatable address
Alex Hung <alex.hung(a)amd.com>
drm/amd/display: Initialize denominator defaults to 1
Tom Chung <chiahsuan.chung(a)amd.com>
drm/amd/display: Use HW lock mgr for PSR1
Xiang Zhang <hawkxiang.cpp(a)gmail.com>
scsi: iscsi: Fix redundant response for ISCSI_UEVENT_GET_HOST_STATS request
Maciej Strozek <mstrozek(a)opensource.cirrus.com>
ASoC: cs42l43: Add codec force suspend/resume ops
Linus Walleij <linus.walleij(a)linaro.org>
seccomp: Stub for !CONFIG_SECCOMP
Charles Keepax <ckeepax(a)opensource.cirrus.com>
ASoC: samsung: Add missing selects for MFD_WM8994
Marian Postevca <posteuca(a)mutex.one>
ASoC: codecs: es8316: Fix HW rate calculation for 48Mhz MCLK
Charles Keepax <ckeepax(a)opensource.cirrus.com>
ASoC: wm8994: Add depends on MFD core
-------------
Diffstat:
Makefile | 4 +-
.../gpu/drm/amd/display/dc/dce/dmub_hw_lock_mgr.c | 3 +-
.../dml21/src/dml2_core/dml2_core_dcn4_calcs.c | 4 +-
drivers/gpu/drm/drm_connector.c | 3 +
drivers/hid/hid-ids.h | 1 -
drivers/hid/hid-multitouch.c | 8 +-
drivers/hid/wacom_sys.c | 24 +--
drivers/hwmon/drivetemp.c | 2 +-
drivers/input/joystick/xpad.c | 9 +-
drivers/input/keyboard/atkbd.c | 2 +-
drivers/irqchip/irq-sunxi-nmi.c | 3 +-
drivers/net/wireless/realtek/rtl8xxxu/core.c | 20 +++
drivers/of/unittest-data/tests-platform.dtsi | 13 ++
drivers/of/unittest.c | 14 ++
drivers/scsi/scsi_transport_iscsi.c | 4 +-
drivers/scsi/storvsc_drv.c | 8 +-
drivers/usb/gadget/function/u_serial.c | 8 +-
drivers/usb/serial/quatech2.c | 2 +-
drivers/vfio/platform/vfio_platform_common.c | 10 ++
fs/gfs2/file.c | 1 +
fs/libfs.c | 162 ++++++++++-----------
fs/smb/client/smb2inode.c | 104 +++++++++----
include/linux/fs.h | 1 -
include/linux/seccomp.h | 2 +-
io_uring/rsrc.c | 7 +
mm/filemap.c | 19 +++
mm/shmem.c | 4 +-
mm/zswap.c | 90 ++++++++----
net/sched/sch_ets.c | 2 +
sound/pci/hda/patch_realtek.c | 4 +-
sound/soc/codecs/Kconfig | 1 +
sound/soc/codecs/cs42l43.c | 1 +
sound/soc/codecs/es8316.c | 10 +-
sound/soc/samsung/Kconfig | 6 +-
sound/usb/quirks.c | 2 +
35 files changed, 374 insertions(+), 184 deletions(-)
Hello,
While experimenting with bbr protocol, I manipulated the network conditions by maintaining a high RTT for about one second before abruptly reducing it. Some packets sent during the high RTT phase experienced long delays in reaching the destination, while later packets, benefiting from the lower RTT, arrived earlier. This out-of-order arrival triggered the receiver to generate duplicate acknowledgments (dup ACKs). Due to the low RTT, these dup ACKs quickly reached the sender. Upon receiving three dup ACKs, the sender initiated a fast retransmission for an earlier packet that was not lost but was simply taking longer to arrive. Interestingly, despite the fast-retransmitted packet experienced a lower RTT, the original delayed packet still arrived first. When the receiver received this packet, it sent an ACK for the next packet in sequence. However, upon later receiving the fast-retransmitted packet, an issue arose in its logic for updating the acknowledgment number. As a result, even after the next expected packet was received, the acknowledgment number was not updated correctly. The receiver continued sending dup ACKs, ultimately forcing bbr into the retransmission timeout (RTO) phase.
I generated this issue in linux kernel version 5.15.0-117-generic with Ubuntu 20.04. I attempted to confirm whether the issue persists with the latest Linux kernel. However, I discovered that the behavior of bbr has changed in the most recent kernel version, where it now sends chunks of packets instead of sending them one by one over time. As a result, I was unable to reproduce the specific sequence of events that triggered the bug we identified. Consequently, I could not confirm whether the bug still exists in the latest kernel.
I believe that the issue (if still exists) will have to be resolved in the location net/ipv4/tcp_input.c or something like that. There are so many authors here that I do not know who to CC here. So, sending this email to you. Sorry if this is not the best way to report this issue.
Thanks
Shehab
________________________________________
From: Ahmed, Shehab Sarar
Sent: Saturday, February 1, 2025 1:01 PM
To: stable(a)vger.kernel.org
Cc: regressions(a)lists.linux.dev
Subject: TCP Fast Retransmission Issue
Hello,
While experimenting with bbr protocol, I manipulated the network conditions by maintaining a high RTT for about one second before abruptly reducing it. Some packets sent during the high RTT phase experienced long delays in reaching the destination, while later packets, benefiting from the lower RTT, arrived earlier. This out-of-order arrival triggered the receiver to generate duplicate acknowledgments (dup ACKs). Due to the low RTT, these dup ACKs quickly reached the sender. Upon receiving three dup ACKs, the sender initiated a fast retransmission for an earlier packet that was not lost but was simply taking longer to arrive. Interestingly, despite the fast-retransmitted packet experienced a lower RTT, the original delayed packet still arrived first. When the receiver received this packet, it sent an ACK for the next packet in sequence. However, upon later receiving the fast-retransmitted packet, an issue arose in its logic for updating the acknowledgment number. As a result, even after the next expected packet was received, the acknowledgment number was not updated correctly. The receiver continued sending dup ACKs, ultimately forcing bbr into the retransmission timeout (RTO) phase.
I generated this issue in linux kernel version 5.15.0-117-generic with Ubuntu 20.04. I attempted to confirm whether the issue persists with the latest Linux kernel. However, I discovered that the behavior of bbr has changed in the most recent kernel version, where it now sends chunks of packets instead of sending them one by one over time. As a result, I was unable to reproduce the specific sequence of events that triggered the bug we identified. Consequently, I could not confirm whether the bug still exists in the latest kernel.
I believe that the issue (if still exists) will have to be resolved in the location net/ipv4/tcp_input.c or something like that. There are so many authors here that I do not know who to CC here. So, sending this email to you. Sorry if this is not the best way to report this issue.
Thanks
Shehab
Returning to focus on 6.1, here is the 6.1 set from the corresponding
6.6 set:
https://lore.kernel.org/all/20240208232054.15778-1-catherine.hoang@oracle.c…
Two patches are missing from the original set:
[01/21] MAINTAINERS: add Catherine as xfs maintainer for 6.6.y
6.6.y-only change
[16/21] xfs: fix again select in kconfig XFS_ONLINE_SCRUB_STATS
XFS_ONLINE_SCRUB_STATS didn't show up till 6.6
The auto group was run on 10 configs and no regressions were seen.
This has been ack'd on the xfs-stable mailing list.
Thanks,
Leah
Catherine Hoang (1):
xfs: allow read IO and FICLONE to run concurrently
Cheng Lin (1):
xfs: introduce protection for drop nlink
Christoph Hellwig (4):
xfs: handle nimaps=0 from xfs_bmapi_write in xfs_alloc_file_space
xfs: only remap the written blocks in xfs_reflink_end_cow_extent
xfs: clean up FS_XFLAG_REALTIME handling in xfs_ioctl_setattr_xflags
xfs: respect the stable writes flag on the RT device
Darrick J. Wong (8):
xfs: bump max fsgeom struct version
xfs: hoist freeing of rt data fork extent mappings
xfs: prevent rt growfs when quota is enabled
xfs: rt stubs should return negative errnos when rt disabled
xfs: fix units conversion error in xfs_bmap_del_extent_delay
xfs: make sure maxlen is still congruent with prod when rounding down
xfs: clean up dqblk extraction
xfs: dquot recovery does not validate the recovered dquot
Dave Chinner (1):
xfs: inode recovery does not validate the recovered inode
Leah Rumancik (1):
xfs: up(ic_sema) if flushing data device fails
Long Li (2):
xfs: factor out xfs_defer_pending_abort
xfs: abort intent items when recovery intents fail
Omar Sandoval (1):
xfs: fix internal error from AGFL exhaustion
fs/xfs/libxfs/xfs_alloc.c | 27 ++++++++++++--
fs/xfs/libxfs/xfs_bmap.c | 21 +++--------
fs/xfs/libxfs/xfs_defer.c | 28 +++++++++------
fs/xfs/libxfs/xfs_defer.h | 2 +-
fs/xfs/libxfs/xfs_inode_buf.c | 3 ++
fs/xfs/libxfs/xfs_rtbitmap.c | 33 +++++++++++++++++
fs/xfs/libxfs/xfs_sb.h | 2 +-
fs/xfs/xfs_bmap_util.c | 24 +++++++------
fs/xfs/xfs_dquot.c | 5 +--
fs/xfs/xfs_dquot_item_recover.c | 21 +++++++++--
fs/xfs/xfs_file.c | 63 ++++++++++++++++++++++++++-------
fs/xfs/xfs_inode.c | 24 +++++++++++++
fs/xfs/xfs_inode.h | 17 +++++++++
fs/xfs/xfs_inode_item_recover.c | 14 +++++++-
fs/xfs/xfs_ioctl.c | 30 ++++++++++------
fs/xfs/xfs_iops.c | 7 ++++
fs/xfs/xfs_log.c | 23 ++++++------
fs/xfs/xfs_log_recover.c | 2 +-
fs/xfs/xfs_reflink.c | 5 +++
fs/xfs/xfs_rtalloc.c | 33 +++++++++++++----
fs/xfs/xfs_rtalloc.h | 27 ++++++++------
21 files changed, 310 insertions(+), 101 deletions(-)
--
2.48.1.362.g079036d154-goog
From: Tejun Heo <tj(a)kernel.org>
[ Upstream commit 86e6ca55b83c575ab0f2e105cf08f98e58d3d7af ]
blkcg_unpin_online() walks up the blkcg hierarchy putting the online pin. To
walk up, it uses blkcg_parent(blkcg) but it was calling that after
blkcg_destroy_blkgs(blkcg) which could free the blkcg, leading to the
following UAF:
==================================================================
BUG: KASAN: slab-use-after-free in blkcg_unpin_online+0x15a/0x270
Read of size 8 at addr ffff8881057678c0 by task kworker/9:1/117
CPU: 9 UID: 0 PID: 117 Comm: kworker/9:1 Not tainted 6.13.0-rc1-work-00182-gb8f52214c61a-dirty #48
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS unknown 02/02/2022
Workqueue: cgwb_release cgwb_release_workfn
Call Trace:
<TASK>
dump_stack_lvl+0x27/0x80
print_report+0x151/0x710
kasan_report+0xc0/0x100
blkcg_unpin_online+0x15a/0x270
cgwb_release_workfn+0x194/0x480
process_scheduled_works+0x71b/0xe20
worker_thread+0x82a/0xbd0
kthread+0x242/0x2c0
ret_from_fork+0x33/0x70
ret_from_fork_asm+0x1a/0x30
</TASK>
...
Freed by task 1944:
kasan_save_track+0x2b/0x70
kasan_save_free_info+0x3c/0x50
__kasan_slab_free+0x33/0x50
kfree+0x10c/0x330
css_free_rwork_fn+0xe6/0xb30
process_scheduled_works+0x71b/0xe20
worker_thread+0x82a/0xbd0
kthread+0x242/0x2c0
ret_from_fork+0x33/0x70
ret_from_fork_asm+0x1a/0x30
Note that the UAF is not easy to trigger as the free path is indirected
behind a couple RCU grace periods and a work item execution. I could only
trigger it with artifical msleep() injected in blkcg_unpin_online().
Fix it by reading the parent pointer before destroying the blkcg's blkg's.
Signed-off-by: Tejun Heo <tj(a)kernel.org>
Reported-by: Abagail ren <renzezhongucas(a)gmail.com>
Suggested-by: Linus Torvalds <torvalds(a)linuxfoundation.org>
Fixes: 4308a434e5e0 ("blkcg: don't offline parent blkcg first")
Cc: stable(a)vger.kernel.org # v5.7+
Signed-off-by: Jens Axboe <axboe(a)kernel.dk>
Signed-off-by: Andrea Ciprietti <ciprietti(a)google.com>
---
include/linux/blk-cgroup.h | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index 0e6e84db06f6..b89099360a86 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -428,10 +428,14 @@ static inline void blkcg_pin_online(struct blkcg *blkcg)
static inline void blkcg_unpin_online(struct blkcg *blkcg)
{
do {
+ struct blkcg *parent;
+
if (!refcount_dec_and_test(&blkcg->online_pin))
break;
+
+ parent = blkcg_parent(blkcg);
blkcg_destroy_blkgs(blkcg);
- blkcg = blkcg_parent(blkcg);
+ blkcg = parent;
} while (blkcg);
}
--
2.48.1.262.g85cc9f2d1e-goog