Max Makarov reported kernel panic [1] in perf user callchain code.
The reason for that is the race between uprobe_free_utask and bpf
profiler code doing the perf user stack unwind and is triggered
within uprobe_free_utask function:
- after current->utask is freed and
- before current->utask is set to NULL
general protection fault, probably for non-canonical address 0x9e759c37ee555c76: 0000 [#1] SMP PTI
RIP: 0010:is_uprobe_at_func_entry+0x28/0x80
...
? die_addr+0x36/0x90
? exc_general_protection+0x217/0x420
? asm_exc_general_protection+0x26/0x30
? is_uprobe_at_func_entry+0x28/0x80
perf_callchain_user+0x20a/0x360
get_perf_callchain+0x147/0x1d0
bpf_get_stackid+0x60/0x90
bpf_prog_9aac297fb833e2f5_do_perf_event+0x434/0x53b
? __smp_call_single_queue+0xad/0x120
bpf_overflow_handler+0x75/0x110
...
asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__kmem_cache_free+0x1cb/0x350
...
? uprobe_free_utask+0x62/0x80
? acct_collect+0x4c/0x220
uprobe_free_utask+0x62/0x80
mm_release+0x12/0xb0
do_exit+0x26b/0xaa0
__x64_sys_exit+0x1b/0x20
do_syscall_64+0x5a/0x80
It can be easily reproduced by running following commands in
separate terminals:
# while :; do bpftrace -e 'uprobe:/bin/ls:_start { printf("hit\n"); }' -c ls; done
# bpftrace -e 'profile:hz:100000 { @[ustack()] = count(); }'
Fixing this by making sure current->utask pointer is set to NULL
before we start to release the utask object.
[1] https://github.com/grafana/pyroscope/issues/3673
Fixes: cfa7f3d2c5 ("perf,x86: avoid missing caller address in stack traces captured in uprobe")
Reported-by: Max Makarov <maxpain@linux.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20250109141440.2692173-1-jolsa@kernel.org
Mediatek DRM Fixes - 20250104
1. Revert "drm/mediatek: dsi: Correct calculation formula of PHY Timing"
2. Set private->all_drm_private[i]->drm to NULL if mtk_drm_bind returns err
3. Move mtk_crtc_finish_page_flip() to ddp_cmdq_cb()
4. Only touch DISP_REG_OVL_PITCH_MSB if AFBC is supported
5. Add support for 180-degree rotation in the display driver
6. Stop selecting foreign drivers
7. Revert "drm/mediatek: Switch to for_each_child_of_node_scoped()"
8. Fix YCbCr422 color format issue for DP
9. Fix mode valid issue for dp
10. dp: Reference common DAI properties
11. dsi: Add registers to pdata to fix MT8186/MT8188
12. Remove unneeded semicolon
13. Add return value check when reading DPCD
14. Initialize pointer in mtk_drm_of_ddp_path_build_one()
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20250104124227.45505-1-chunkuang.hu@kernel.org
Pull smb server fixes from Steve French:
"Four ksmbd server fixes, most also for stable:
- fix for reporting special file type more accurately when POSIX
extensions negotiated
- minor cleanup
- fix possible incorrect creation path when dirname is not present.
In some cases, Windows apps create files without checking if they
exist.
- fix potential NULL pointer dereference sending interim response"
* tag '6.13-rc6-ksmbd-server-fixes' of git://git.samba.org/ksmbd:
ksmbd: Implement new SMB3 POSIX type
ksmbd: fix unexpectedly changed path in ksmbd_vfs_kern_path_locked
ksmbd: Remove unneeded if check in ksmbd_rdma_capable_netdev()
ksmbd: fix a missing return value check bug
Remove misplaced colon in stm32_firewall_get_firewall()
which results in a syntax error when the code is compiled
without CONFIG_STM32_FIREWALL.
Fixes: 5c9668cfc6 ("firewall: introduce stm32_firewall framework")
Signed-off-by: guanjing <guanjing@cmss.chinamobile.com>
Reviewed-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
i.MX fixes for 6.13:
- Add fallback for i.MX8QM ESAI compatible to fix a dt-schema warning
caused by bindings update
- Fix uSDHC1 clock for i.MX RT1050
- Enable SND_SOC_SPDIF in imx_v6_v7_defconfig to fix a regression caused
by an i.MX6 SPDIF sound card change in DT
- Fix address length of i.MX95 netcmix_blk_ctrl
* tag 'imx-fixes-6.13' of https://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux:
ARM: dts: imxrt1050: Fix clocks for mmc
ARM: imx_v6_v7_defconfig: enable SND_SOC_SPDIF
arm64: dts: imx95: correct the address length of netcmix_blk_ctrl
arm64: dts: imx8-ss-audio: add fallback compatible string fsl,imx6ull-esai for esai
Link: https://lore.kernel.org/r/Z3Jf9zbv/xH3YzuB@dragon
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Qualcomm Arm64 DeviceTree fixes for v6.13
Revert the enablement of OTG support on primary and secondary USB Type-C
controllers of X1 Elite, for now, as this broke support for USB hotplug.
Disable the TPDM DCC device on SA8775P, as this is inaccessible per
current firmware configuration. Also correct the PCIe "addr_space"
region to enable larger BAR sizes.
Also fix the address space of PCIe6a found in X1 Elite.
* tag 'qcom-arm64-fixes-for-6.13' of https://git.kernel.org/pub/scm/linux/kernel/git/qcom/linux:
arm64: dts: qcom: sa8775p: fix the secure device bootup issue
Revert "arm64: dts: qcom: x1e80100: enable OTG on USB-C controllers"
Revert "arm64: dts: qcom: x1e80100-crd: enable otg on usb ports"
arm64: dts: qcom: x1e80100: Fix up BAR space size for PCIe6a
Revert "arm64: dts: qcom: x1e78100-t14s: enable otg on usb-c ports"
arm64: dts: qcom: sa8775p: Fix the size of 'addr_space' regions
Link: https://lore.kernel.org/r/20250103024945.4649-1-andersson@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Pull networking fixes from Jakub Kicinski:
"Including fixes from netfilter, Bluetooth and WPAN.
No outstanding fixes / investigations at this time.
Current release - new code bugs:
- eth: fbnic: revert HWMON support, it doesn't work at all and revert
is similar size as the fixes
Previous releases - regressions:
- tcp: allow a connection when sk_max_ack_backlog is zero
- tls: fix tls_sw_sendmsg error handling
Previous releases - always broken:
- netdev netlink family:
- prevent accessing NAPI instances from another namespace
- don't dump Tx and uninitialized NAPIs
- net: sysctl: avoid using current->nsproxy, fix null-deref if task
is exiting and stick to opener's netns
- sched: sch_cake: add bounds checks to host bulk flow fairness
counts
Misc:
- annual cleanup of inactive maintainers"
* tag 'net-6.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (57 commits)
rds: sysctl: rds_tcp_{rcv,snd}buf: avoid using current->nsproxy
sctp: sysctl: plpmtud_probe_interval: avoid using current->nsproxy
sctp: sysctl: udp_port: avoid using current->nsproxy
sctp: sysctl: auth_enable: avoid using current->nsproxy
sctp: sysctl: rto_min/max: avoid using current->nsproxy
sctp: sysctl: cookie_hmac_alg: avoid using current->nsproxy
mptcp: sysctl: blackhole timeout: avoid using current->nsproxy
mptcp: sysctl: sched: avoid using current->nsproxy
mptcp: sysctl: avail sched: remove write access
MAINTAINERS: remove Lars Povlsen from Microchip Sparx5 SoC
MAINTAINERS: remove Noam Dagan from AMAZON ETHERNET
MAINTAINERS: remove Ying Xue from TIPC
MAINTAINERS: remove Mark Lee from MediaTek Ethernet
MAINTAINERS: mark stmmac ethernet as an Orphan
MAINTAINERS: remove Andy Gospodarek from bonding
MAINTAINERS: update maintainers for Microchip LAN78xx
MAINTAINERS: mark Synopsys DW XPCS as Orphan
net/mlx5: Fix variable not being completed when function returns
rtase: Fix a check for error in rtase_alloc_msix()
net: stmmac: dwmac-tegra: Read iommu stream id from device tree
...
Pull btrfs fixes from David Sterba:
"A few more fixes.
Besides the one-liners in Btrfs there's fix to the io_uring and
encoded read integration (added in this development cycle). The update
to io_uring provides more space for the ongoing command that is then
used in Btrfs to handle some cases.
- io_uring and encoded read:
- provide stable storage for io_uring command data
- make a copy of encoded read ioctl call, reuse that in case the
call would block and will be called again
- properly initialize zlib context for hardware compression on s390
- fix max extent size calculation on filesystems with non-zoned
devices
- fix crash in scrub on crafted image due to invalid extent tree"
* tag 'for-6.13-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: zlib: fix avail_in bytes for s390 zlib HW compression path
btrfs: zoned: calculate max_extent_size properly on non-zoned setup
btrfs: avoid NULL pointer dereference if no valid extent tree
btrfs: don't read from userspace twice in btrfs_uring_encoded_read()
io_uring: add io_uring_cmd_get_async_data helper
io_uring/cmd: add per-op data to struct io_uring_cmd_data
io_uring/cmd: rename struct uring_cache to io_uring_cmd_data
Atish Patra <atishp@rivosinc.com> says:
Here are two minor improvement/fixes in the PMU event path. The first patch
was part of the series[1]. The 2nd patch was suggested during the series
review.
While the series can only be merged once SBI v3.0 is frozen, these two
patches can be independent of SBI v3.0 and can be merged sooner. Hence, these
two patches are sent as a separate series.
* b4-shazam-merge:
drivers/perf: riscv: Do not allow invalid raw event config
drivers/perf: riscv: Return error for default case
drivers/perf: riscv: Fix Platform firmware event data
Link: https://lore.kernel.org/r/20241212-pmu_event_fixes_v2-v2-0-813e8a4f5962@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The SBI specification allows only lower 48bits of hpmeventX to be
configured via SBI PMU. Currently, the driver masks of the higher
bits but doesn't return an error. This will lead to an additional
SBI call for config matching which should return for an invalid
event error in most of the cases.
However, if a platform(i.e Rocket and sifive cores) implements a
bitmap of all bits in the event encoding this will lead to an
incorrect event being programmed leading to user confusion.
Report the error to the user if higher bits are set during the
event mapping itself to avoid the confusion and save an additional
SBI call.
Suggested-by: Samuel Holland <samuel.holland@sifive.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20241212-pmu_event_fixes_v2-v2-3-813e8a4f5962@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Platform firmware event data field is allowed to be 62 bits for
Linux as uppper most two bits are reserved to indicate SBI fw or
platform specific firmware events.
However, the event data field is masked as per the hardware raw
event mask which is not correct.
Fix the platform firmware event data field with proper mask.
Fixes: f0c9363db2 ("perf/riscv-sbi: Add platform specific firmware event handling")
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20241212-pmu_event_fixes_v2-v2-1-813e8a4f5962@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This contains a pair of fixes for the vector self tests, which avoids
some warnings and provides proper status messages.
* b4-shazam-merge:
tools: selftests: riscv: Add test count for vstate_prctl
tools: selftests: riscv: Add pass message for v_initval_nolibc
Link: https://lore.kernel.org/r/20241220091730.28006-1-yongxuan.wang@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains Netfilter fixes for net:
1) Fix imbalance between flowtable BIND and UNBIND calls to configure
hardware offload, this fixes a possible kmemleak.
2) Clamp maximum conntrack hashtable size to INT_MAX to fix a possible
WARN_ON_ONCE splat coming from kvmalloc_array(), only possible from
init_netns.
* tag 'nf-25-01-09' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
netfilter: conntrack: clamp maximum hashtable size to INT_MAX
netfilter: nf_tables: imbalance in flowtable binding
====================
Link: https://patch.msgid.link/20250109123532.41768-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Matthieu Baerts says:
====================
net: sysctl: avoid using current->nsproxy
As pointed out by Al Viro and Eric Dumazet in [1], using the 'net'
structure via 'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only
from the opener's netns as it is usually done. This could cause
unexpected issues when other operations are done on the wrong netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
(null-ptr-deref), e.g. when the current task is exiting, as spotted by
syzbot [1] using acct(2).
The 'net' or 'pernet' structure can be obtained from the table->data
using container_of().
Note that table->data could also be used directly in more places, but
that would increase the size of this fix to replace all accesses via
'net'. Probably best to avoid that for fixes.
Patches 2-9 remove access of net via current->nsproxy in sysfs handlers
in MPTCP, SCTP and RDS. There are multiple patches doing almost the same
thing, but the reason is to ease the backports.
Patch 1 is not directly linked to this, but it is a small fix for MPTCP
available_schedulers sysctl knob to explicitly mark it as read-only.
Please note that this series does not address Al's comment [2]. In SCTP,
some sysctl knobs set other sysfs-exposed variables for the min/max: two
processes could then write two linked values at the same time, resulting
in new values being outside the new boundaries. It would be great if
SCTP developers can look at this problem.
Link: https://lore.kernel.org/67769ecb.050a0220.3a8527.003f.GAE@google.com [1]
Link: https://lore.kernel.org/20250105211158.GL1977892@ZenIV [2]
====================
Link: https://patch.msgid.link/20250108-net-sysctl-current-nsproxy-v1-0-5df34b2083e8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As mentioned in a previous commit of this series, using the 'net'
structure via 'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only
from the opener's netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
(null-ptr-deref), e.g. when the current task is exiting, as spotted by
syzbot [1] using acct(2).
The per-netns structure can be obtained from the table->data using
container_of(), then the 'net' one can be retrieved from the listen
socket (if available).
Fixes: c6a58ffed5 ("RDS: TCP: Add sysctl tunables for sndbuf/rcvbuf on rds-tcp socket")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/67769ecb.050a0220.3a8527.003f.GAE@google.com [1]
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250108-net-sysctl-current-nsproxy-v1-9-5df34b2083e8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As mentioned in a previous commit of this series, using the 'net'
structure via 'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only
from the opener's netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
(null-ptr-deref), e.g. when the current task is exiting, as spotted by
syzbot [1] using acct(2).
The 'net' structure can be obtained from the table->data using
container_of().
Note that table->data could also be used directly, as this is the only
member needed from the 'net' structure, but that would increase the size
of this fix, to use '*data' everywhere 'net->sctp.probe_interval' is
used.
Fixes: d1e462a7a5 ("sctp: add probe_interval in sysctl and sock/asoc/transport")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/67769ecb.050a0220.3a8527.003f.GAE@google.com [1]
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250108-net-sysctl-current-nsproxy-v1-8-5df34b2083e8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As mentioned in a previous commit of this series, using the 'net'
structure via 'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only
from the opener's netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
(null-ptr-deref), e.g. when the current task is exiting, as spotted by
syzbot [1] using acct(2).
The 'net' structure can be obtained from the table->data using
container_of().
Note that table->data could also be used directly, but that would
increase the size of this fix, while 'sctp.ctl_sock' still needs to be
retrieved from 'net' structure.
Fixes: 046c052b47 ("sctp: enable udp tunneling socks")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/67769ecb.050a0220.3a8527.003f.GAE@google.com [1]
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250108-net-sysctl-current-nsproxy-v1-7-5df34b2083e8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As mentioned in a previous commit of this series, using the 'net'
structure via 'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only
from the opener's netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
(null-ptr-deref), e.g. when the current task is exiting, as spotted by
syzbot [1] using acct(2).
The 'net' structure can be obtained from the table->data using
container_of().
Note that table->data could also be used directly, but that would
increase the size of this fix, while 'sctp.ctl_sock' still needs to be
retrieved from 'net' structure.
Fixes: b14878ccb7 ("net: sctp: cache auth_enable per endpoint")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/67769ecb.050a0220.3a8527.003f.GAE@google.com [1]
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250108-net-sysctl-current-nsproxy-v1-6-5df34b2083e8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As mentioned in a previous commit of this series, using the 'net'
structure via 'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only
from the opener's netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
(null-ptr-deref), e.g. when the current task is exiting, as spotted by
syzbot [1] using acct(2).
The 'net' structure can be obtained from the table->data using
container_of().
Note that table->data could also be used directly, as this is the only
member needed from the 'net' structure, but that would increase the size
of this fix, to use '*data' everywhere 'net->sctp.rto_min/max' is used.
Fixes: 4f3fdf3bc5 ("sctp: add check rto_min and rto_max in sysctl")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/67769ecb.050a0220.3a8527.003f.GAE@google.com [1]
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250108-net-sysctl-current-nsproxy-v1-5-5df34b2083e8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As mentioned in a previous commit of this series, using the 'net'
structure via 'current' is not recommended for different reasons:
- Inconsistency: getting info from the reader's/writer's netns vs only
from the opener's netns.
- current->nsproxy can be NULL in some cases, resulting in an 'Oops'
(null-ptr-deref), e.g. when the current task is exiting, as spotted by
syzbot [1] using acct(2).
The 'net' structure can be obtained from the table->data using
container_of().
Note that table->data could also be used directly, as this is the only
member needed from the 'net' structure, but that would increase the size
of this fix, to use '*data' everywhere 'net->sctp.sctp_hmac_alg' is
used.
Fixes: 3c68198e75 ("sctp: Make hmac algorithm selection for cookie generation dynamic")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/67769ecb.050a0220.3a8527.003f.GAE@google.com [1]
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250108-net-sysctl-current-nsproxy-v1-4-5df34b2083e8@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Netfslib needs to be able to handle kernel-initiated asynchronous DIO that
is supplied with a bio_vec[] array. Currently, because of the async flag,
this gets passed to netfs_extract_user_iter() which throws a warning and
fails because it only handles IOVEC and UBUF iterators. This can be
triggered through a combination of cifs and a loopback blockdev with
something like:
mount //my/cifs/share /foo
dd if=/dev/zero of=/foo/m0 bs=4K count=1K
losetup --sector-size 4096 --direct-io=on /dev/loop2046 /foo/m0
echo hello >/dev/loop2046
This causes the following to appear in syslog:
WARNING: CPU: 2 PID: 109 at fs/netfs/iterator.c:50 netfs_extract_user_iter+0x170/0x250 [netfs]
and the write to fail.
Fix this by removing the check in netfs_unbuffered_write_iter_locked() that
causes async kernel DIO writes to be handled as userspace writes. Note
that this change relies on the kernel caller maintaining the existence of
the bio_vec array (or kvec[] or folio_queue) until the op is complete.
Fixes: 153a9961b5 ("netfs: Implement unbuffered/DIO write support")
Reported-by: Nicolas Baranger <nicolas.baranger@3xo.fr>
Closes: https://lore.kernel.org/r/fedd8a40d54b2969097ffa4507979858@3xo.fr/
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/608725.1736275167@warthog.procyon.org.uk
Tested-by: Nicolas Baranger <nicolas.baranger@3xo.fr>
Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
cc: Steve French <smfrench@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Even though we fixed a logic error in the commit cited below, syzbot
still managed to trigger an underflow of the per-host bulk flow
counters, leading to an out of bounds memory access.
To avoid any such logic errors causing out of bounds memory accesses,
this commit factors out all accesses to the per-host bulk flow counters
to a series of helpers that perform bounds-checking before any
increments and decrements. This also has the benefit of improving
readability by moving the conditional checks for the flow mode into
these helpers, instead of having them spread out throughout the
code (which was the cause of the original logic error).
As part of this change, the flow quantum calculation is consolidated
into a helper function, which means that the dithering applied to the
ost load scaling is now applied both in the DRR rotation and when a
sparse flow's quantum is first initiated. The only user-visible effect
of this is that the maximum packet size that can be sent while a flow
stays sparse will now vary with +/- one byte in some cases. This should
not make a noticeable difference in practice, and thus it's not worth
complicating the code to preserve the old behaviour.
Fixes: 546ea84d07 ("sched: sch_cake: fix bulk flow accounting logic for host fairness")
Reported-by: syzbot+f63600d288bfb7057424@syzkaller.appspotmail.com
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Dave Taht <dave.taht@gmail.com>
Link: https://patch.msgid.link/20250107120105.70685-1-toke@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Bring in the fix for the mount namespace rbtree. It is used as the base
for the vfs mount work for this cycle and so shouldn't be applied
directly.
Signed-off-by: Christian Brauner <brauner@kernel.org>
Move mnt->mnt_node into the union with mnt->mnt_rcu and mnt->mnt_llist
instead of keeping it with mnt->mnt_list. This allows us to use
RB_CLEAR_NODE(&mnt->mnt_node) in umount_tree() as well as
list_empty(&mnt->mnt_node). That in turn allows us to remove MNT_ONRB.
This also fixes the bug reported in [1] where seemingly MNT_ONRB wasn't
set in @mnt->mnt_flags even though the mount was present in the mount
rbtree of the mount namespace.
The root cause is the following race. When a btrfs subvolume is mounted
a temporary mount is created:
btrfs_get_tree_subvol()
{
mnt = fc_mount()
// Register the newly allocated mount with sb->mounts:
lock_mount_hash();
list_add_tail(&mnt->mnt_instance, &mnt->mnt.mnt_sb->s_mounts);
unlock_mount_hash();
}
and registered on sb->s_mounts. Later it is added to an anonymous mount
namespace via mount_subvol():
-> mount_subvol()
-> mount_subtree()
-> alloc_mnt_ns()
mnt_add_to_ns()
vfs_path_lookup()
put_mnt_ns()
The mnt_add_to_ns() call raises MNT_ONRB in @mnt->mnt_flags. If someone
concurrently does a ro remount:
reconfigure_super()
-> sb_prepare_remount_readonly()
{
list_for_each_entry(mnt, &sb->s_mounts, mnt_instance) {
}
all mounts registered in sb->s_mounts are visited and first
MNT_WRITE_HOLD is raised, then MNT_READONLY is raised, and finally
MNT_WRITE_HOLD is removed again.
The flag modification for MNT_WRITE_HOLD/MNT_READONLY and MNT_ONRB race
so MNT_ONRB might be lost.
Fixes: 2eea9ce431 ("mounts: keep list of mounts in an rbtree")
Cc: <stable@kernel.org> # v6.8+
Link: https://lore.kernel.org/r/20241215-vfs-6-14-mount-work-v1-1-fd55922c4af8@kernel.org
Link: https://lore.kernel.org/r/ec6784ed-8722-4695-980a-4400d4e7bd1a@gmx.com [1]
Signed-off-by: Christian Brauner <brauner@kernel.org>
