linux/include
Junrui Luo c75ef2137e NFSv4.2: fix LAYOUTSTATS send buffer exhaustion
encode_layoutstats_maxsz budgets XDR_QUADLEN(PNFS_LAYOUTSTATS_MAXSIZE),
i.e. 256 bytes, for the layoutupdate4 body written by the layout driver.
The flexfiles record can exceed that.

ff_layout_encode_ff_layoutupdate() emits, per data server, a netaddr4,
an nfs_fh4, two ff_io_latency4, an nfstime4 and a bool.  A data server
whose filehandle is NFS_MAXFHSIZE bytes long already accounts for 132 of
those bytes, and the two ff_io_latency4 at 64 bytes each, the nfstime4
and the bool add a further 144, so the body passes 256 bytes before the
netaddr4 is encoded at all.  encode_layoutstats() additionally writes
the deviceid4 and the layoutupdate4 lou_type word, neither of which the
macro accounts for.

The filehandle and the address are both chosen by the server, through
LAYOUTGET and GETDEVICEINFO, so it can drive the encoder past the
end of the send buffer.  xdr_reserve_space() returns NULL once that
happens, and the two ff_layout_encode_io_latency() calls run with
dss_info->mirror->lock held, so a NULL return there leaves the lock
permanently held.

Raise PNFS_LAYOUTSTATS_MAXSIZE to 384 so that the record fits inside the
reservation.

Fixes: 27c4306443 ("pnfs/flexfiles: encode LAYOUTSTATS flexfiles specific data")
Reported-by: Yuhao Jiang <danisjiang@gmail.com>
Assisted-by: Claude:claude-opus-5
Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2026-08-20 15:18:20 -07:00
..
acpi ACPI: CPPC: Check all controls for fast switching 2026-07-22 15:09:14 +02:00
asm-generic mm.git review status for mm-hotfixes-stable..mm-nonmm-stable 2026-06-21 13:20:19 -07:00
clocksource
crypto Networking changes for 7.2. 2026-06-17 08:17:00 +01:00
cxl cxl/region: Introduce devm_cxl_probe_mem() 2026-06-12 13:47:30 -07:00
drm drm-misc-fixes for v7.2-rc5: 2026-07-24 18:30:29 +10:00
dt-bindings SoC fixes for 7.2 2026-07-17 08:52:09 -07:00
hyperv mshv: fix hv_input_get_system_property struct 2026-07-22 21:58:21 +00:00
keys keys: Pin request_key_auth payload in instantiate paths 2026-06-15 15:19:13 +03:00
kunit linux_kselftest-kunit-7.2-rc1 2026-06-16 16:33:57 +05:30
kvm KVM: arm64: vgic: Fix race between LPI release and re-registration 2026-07-23 09:56:57 +01:00
linux NFSv4.2: fix LAYOUTSTATS send buffer exhaustion 2026-08-20 15:18:20 -07:00
math-emu
media
memory
misc
net net/sched: reject overly deep qdisc hierarchies 2026-08-06 15:24:44 +02:00
pcmcia Replace <linux/mod_devicetable.h> by more specific <linux/device-id/*.h> (headers) 2026-07-03 07:38:16 +02:00
ras
rdma RDMA v7.2 merge window 2026-06-18 08:16:21 -07:00
rv
scsi SCSI fixes on 20260802 2026-08-02 09:32:07 -07:00
soc soc/tegra: pmc: Fixes for v7.2 2026-07-10 14:40:52 +02:00
sound ASoC/soundwire: Intel: reset the PCMSyCM registers in hda_sdw_bpt_close 2026-07-31 13:23:10 +01:00
target
trace for-7.2-rc6-fixup-worker-tag 2026-08-06 13:29:15 -07:00
uapi io_uring-7.2-20260724 2026-07-24 19:58:03 -07:00
ufs Merge branch 7.1/scsi-fixes into 7.2/scsi-staging 2026-06-15 21:01:30 -04:00
vdso
video
xen xen: Replace __ASSEMBLY__ with __ASSEMBLER__ in header files 2026-07-01 09:49:52 +02:00
Kbuild