Josef Bacik 1daf52b5ff nfs: fix UAF in direct writes ... [ Upstream commit 17f46b803d ] In production we have been hitting the following warning consistently ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 17 PID: 1800359 at lib/refcount.c:28 refcount_warn_saturate+0x9c/0xe0 Workqueue: nfsiod nfs_direct_write_schedule_work [nfs] RIP: 0010:refcount_warn_saturate+0x9c/0xe0 PKRU: 55555554 Call Trace: <TASK> ? __warn+0x9f/0x130 ? refcount_warn_saturate+0x9c/0xe0 ? report_bug+0xcc/0x150 ? handle_bug+0x3d/0x70 ? exc_invalid_op+0x16/0x40 ? asm_exc_invalid_op+0x16/0x20 ? refcount_warn_saturate+0x9c/0xe0 nfs_direct_write_schedule_work+0x237/0x250 [nfs] process_one_work+0x12f/0x4a0 worker_thread+0x14e/0x3b0 ? ZSTD_getCParams_internal+0x220/0x220 kthread+0xdc/0x120 ? __btf_name_valid+0xa0/0xa0 ret_from_fork+0x1f/0x30 This is because we're completing the nfs_direct_request twice in a row. The source of this is when we have our commit requests to submit, we process them and send them off, and then in the completion path for the commit requests we have if (nfs_commit_end(cinfo.mds)) nfs_direct_write_complete(dreq); However since we're submitting asynchronous requests we sometimes have one that completes before we submit the next one, so we end up calling complete on the nfs_direct_request twice. The only other place we use nfs_generic_commit_list() is in __nfs_commit_inode, which wraps this call in a nfs_commit_begin(); nfs_commit_end(); Which is a common pattern for this style of completion handling, one that is also repeated in the direct code with get_dreq()/put_dreq() calls around where we process events as well as in the completion paths. Fix this by using the same pattern for the commit requests. Before with my 200 node rocksdb stress running this warning would pop every 10ish minutes. With my patch the stress test has been running for several hours without popping. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Sasha Levin <sashal@kernel.org>		2024-04-03 15:11:21 +02:00
..
acpi	ACPI: PM: Add acpi_device_fix_up_power_children() function	2023-11-20 17:31:49 +01:00
asm-generic	mm: Introduce flush_cache_vmap_early()	2024-02-16 19:14:25 +01:00
clocksource
crypto	crypto: af_alg - Disallow multiple in-flight AIO requests	2024-01-25 15:44:41 -08:00
drm	drm: Fix drm_fixp2int_round() making it add 0.5	2024-03-26 18:18:56 -04:00
dt-bindings	clk: renesas: r8a779g0: Correct PFC/GPIO parent clocks	2024-03-26 18:18:33 -04:00
keys
kunit	kunit: Add a macro to wrap a deferred action function	2024-03-01 13:41:44 +01:00
kvm	KVM/arm64 updates for 6.7	2023-10-31 16:37:07 -04:00
linux	nfs: fix UAF in direct writes	2024-04-03 15:11:21 +02:00
math-emu
media	media: mc: Add num_links flag to media_pad	2024-04-03 15:11:08 +02:00
memory
misc
net	mac802154: fix llsec key resources release in mac802154_llsec_key_del	2024-04-03 15:11:19 +02:00
pcmcia
ras
rdma	RDMA/core: Fix umem iterator when PAGE_SIZE is greater then HCA pgsz	2023-12-04 20:02:41 -04:00
rv
scsi	scsi: core: Consult supported VPD page list prior to fetching page	2024-03-01 13:41:46 +01:00
soc	soc: qcom: socinfo: rename PM2250 to PM4125	2024-03-26 18:18:05 -04:00
sound	ALSA: hda/tas2781: add ptrs to calibration functions	2024-03-26 18:18:44 -04:00
target
trace	tracing/net_sched: Fix tracepoints that save qdisc_dev() as a string	2024-03-15 10:48:17 -04:00
uapi	uapi: in6: replace temporary label with rfc9486	2024-03-06 14:53:50 +00:00
ufs
vdso
video	fbdev: stifb: Make the STI next font pointer a 32-bit signed offset	2023-10-30 14:54:41 +01:00
xen	xen/events: reduce externally visible helper functions	2023-11-14 09:29:28 +01:00