| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
arm64: mm: Fix the lockless page-table walk in show_pte()
show_pte() walks page tables locklessly and can run with interrupts
enabled. A concurrent teardown can free a table page while it is being
walked. It can also clear a parent entry after show_pte() checked it; the
regular pXd_offset() helpers then reread the cleared entry and can derive a
bogus lower-level pointer and fault again.
Use the lockless offset helpers with the saved parent entries, as
gup_fast() does, and pass the saved PMD to pte_offset_map().
For task page tables, arm64 selects MMU_GATHER_RCU_TABLE_FREE. Disable
local interrupts around the walk to hold off RCU-deferred table frees and
block the tlb_remove_table_sync_one() IPI until the walk is finished.
Place the IRQ guard after the header print. This does not make the output a
consistent snapshot, but prevents the task page-table walk from
dereferencing a released table page or deriving a pointer from a different
parent value. |
| In the Linux kernel, the following vulnerability has been resolved:
s390/vfio-ap: fix potential use of uninitialized apm_filtered bitmap
The DECLARE_BITMAP(apm_filtered, AP_DEVICES) macro allocates the bitmap
on the stack without zero-initializing it.
In vfio_ap_mdev_hot_plug_cfg(), the vfio_ap_mdev_filter_matrix() function
is only called to initialize and populate apm_filtered if either
filter_adapters or filter_domains is true. If the hot plug configuration
change only adds control domains (meaning filter_cdoms is true, but
filter_adapters and filter_domains are both false),
vfio_ap_mdev_filter_matrix() is bypassed.
Consequently, apm_filtered is passed to reset_queues_for_apids() with
uninitialized stack garbage. This can cause reset_queues_for_apids() to
interpret arbitrary stack garbage bits as valid APIDs to reset, potentially
performing unintended guest hardware queue resets.
Fix this by zero-initializing the apm_filtered bitmap at the beginning of
vfio_ap_mdev_hot_plug_cfg() using bitmap_zero(). |
| In the Linux kernel, the following vulnerability has been resolved:
LoongArch: Add DIRECT_MAP_PHYSMEM_END definition
get_free_mem_region() and mhp_get_pluggable_range() bound their search
to DIRECT_MAP_PHYSMEM_END. LoongArch does not define it, so the fallback
in include/linux/mm.h applies: under CONFIG_SPARSEMEM_VMEMMAP it is
(1ULL << MAX_PHYSMEM_BITS) - 1, a compile-time constant that does not
adapt to the CPU's physical address space bits (cpu_pabits, probed from
CPUCFG1).
The vmemmap window only covers physical space below 2^(cpu_pabits+1)
(i.e. VMEMMAP_SIZE), so on CPUs with fewer physical address bits than
MAX_PHYSMEM_BITS the fallback allows get_free_mem_region() to return
a ZONE_DEVICE region outside the vmemmap window; vmemmap_populate() then
wraps the memmap range around and maps it into low memory, silently
corrupting the page tables. The same search also picked the top-of-
address-space region that crashed memmap_init_zone_device() with amdkfd
on Loongson-3C6000 in 6.16 [1]; the commit 2969b42c8f99 ("LoongArch/mm:
align vmemmap to maximal folio size") keeps that region in bounds on
current Loongson-3C6000 configs, but CPUs with smaller cpu_pabits (e.g.
the Loongson-2K series) are still affected.
Define DIRECT_MAP_PHYSMEM_END as the vmemmap-covered physical range,
(1ULL << (cpu_pabits + 1)) - 1, capped at (1ULL << MAX_PHYSMEM_BITS) - 1
under CONFIG_SPARSEMEM, similar to the commit f3336b48cf9d ("riscv: mm:
Define DIRECT_MAP_PHYSMEM_END").
[1] https://lore.kernel.org/amd-gfx/20250814032153.227285-1-jeffbai@aosc.io/ |
| In the Linux kernel, the following vulnerability has been resolved:
media: meson: vdec: fix NULL pointer deref in vdec_try_fmt_common
When VIDIOC_TRY_FMT is called with an unsupported pixel format on the
OUTPUT queue, vdec_try_fmt_common() falls back to V4L2_PIX_FMT_MPEG2.
However, if a distro has locally patched MPEG2 support out (as it has
been broken for some time) the platform format table does not contain
MPEG2 so find_format() returns NULL and the subsequent dereference of
fmt_out->max_width triggers a NULL pointer dereference.
Fix this by falling back to the first format in the platform's format
array instead of hardcoding V4L2_PIX_FMT_MPEG2. This is always valid
since every platform defines at least one format. |
| In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to zero post-EOF data when extending file size
generic/794 4s ... - output mismatch (see /share/git/fstests/results//generic/794.out.bad)
--- tests/generic/794.out 2026-06-12 08:46:32.766426241 +0800
+++ /share/git/fstests/results//generic/794.out.bad 2026-07-05 18:32:55.000000000 +0800
@@ -1,4 +1,16 @@
QA output created by 794
append_write
+FAIL: non-zero data in gap [4080,4096) after shutdown+remount
+000000 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a >ZZZZZZZZZZZZZZZZ<
+*
+001000
truncate_up
...
(Run 'diff -u /share/git/fstests/tests/generic/794.out /share/git/fstests/results//generic/794.out.bad' to see the entire diff)
Ran: generic/794
Failures: generic/794
Failed 1 of 1 tests
Steps of generic/794:
1. write 4096 bytes to file w/ 0x5a
2. use fiemap to get PBA of first block in file
3. truncate file to 4080
4. umount; write 4096 bytes to file w/ 0x5a directly via PBA; mount
5. extend filesize via
a) append 4096 from offset 4096, or
b) truncate 8192, or
c) fallocate 4096 from offset 4096
6. verify the gap is zeroed in memory [4080,4096)
7. sync range 4096 from offset 4096; shutdown -f (flush meta before shutdown)
8. umount; mount; verify [4080,4096) is zeroed or not.
When extending file size (e.g. via truncate, fallocate, or write) across an
unaligned EOF boundary, we need to ensure that post-EOF data in the partial
page is zeroed out in pagecache and marked dirty, then writeback the cache to
persist zeroed data before committing inode w/ updated i_size.
This help to prevent stale disk data beyond the previous EOF from being exposed
after remounting or crash recovery.
Since f2fs is a LFS filesystem, we only support direct write via PBA in pinfile,
and pinfile has section-aligned filesize, so in Android, there should no problem,
but for other usage in different environment, let's fix this w/ fsync_mode=strict
mount option. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/gud: validate TV mode names before creating enum property
The GUD protocol returns TV mode names as fixed-size
GUD_CONNECTOR_TV_MODE_NAME_LEN entries and requires each name to be
NUL-terminated.
gud_connector_add_tv_mode() currently passes each fixed-size entry
directly to drm_mode_create_tv_properties_legacy(), which eventually
reaches drm_property_add_enum() and strlen(). If a device returns an
entry without a terminating NUL byte, strlen() reads past the end of
the slot and can run beyond the allocated buffer, triggering an
out-of-bounds read.
Validate that each returned TV mode name contains a NUL terminator
within its fixed-size slot before passing it to the DRM property code.
If a malformed entry is found, reject the device response with -EIO.
This fixes the out-of-bounds read without changing the handling of
valid devices, and avoids silently truncating malformed protocol data. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/nouveau/dmem: fix callocated underflow on large folio split
nouveau_dmem_folio_free() drops chunk->callocated once per freed folio,
while a large (compound) device-private folio is only counted once when
it is allocated. When such a folio is split, the mm core invokes
->folio_split() (nouveau_dmem_folio_split()) once for each new
sub-folio, but the hook only fixes up the sub-folio metadata and leaves
chunk->callocated unchanged.
Each resulting sub-folio is later freed separately, so after a split
the single allocation (+1) is met by N frees (-N), leaving
chunk->callocated short by N-1. On the first split/free cycle it
underflows: WARN_ON(!chunk->callocated) fires, the unsigned counter
wraps and never returns to zero, so the chunk can no longer be
reclaimed (nouveau_dmem_fini() also warns on the leaked count).
Account for the new sub-folio in the split hook, under the same lock as
nouveau_dmem_folio_free(), so the count stays balanced. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/hugetlb: fix boot panic with CONFIG_DEBUG_VM and HVO bootmem pages
Patch series "mm: Refactor bootmem gigantic hugepage allocation", v4.
This series is split out from the earlier larger series "mm: Generalize
HVO for HugeTLB and device DAX" [1]. It collects the first 19 patches of
that series as a standalone set of fixes and preparatory cleanups around
bootmem HugeTLB handling, sparse initialization ordering, and related
vmemmap setup.
The first patches fix a few bugs found while reviewing the existing code,
including incorrect bootmem HVO handling, wrong vmemmap registration
arguments, a powerpc compound-vmemmap tracking bug, and too-late
initialization of gigantic bootmem HugeTLB struct pages.
The rest of the series reorders early memory initialization so the
relevant zone state is available before sparse and HugeTLB boot-time setup
runs, then simplifies the remaining bootmem gigantic hugepage allocation
path and removes code made obsolete by that rework.
At a high level:
- patches [1-4] fix boot-time and arch-specific bugs
- patches [5-12] reorder and simplify sparse/mm/hugetlb early init
- patches [13-19] refactor bootmem gigantic hugepage allocation and
remove obsolete helpers and state
This patch (of 19):
Commit 622026e87c40 ("mm/hugetlb: remove fake head pages") switched
HVO to reuse per-zone shared tail pages from zone->vmemmap_tails[].
Those shared tail pages were initialized in hugetlb_vmemmap_init(), but
bootmem HugeTLB folios are prepared earlier from
gather_bootmem_prealloc(). With hugetlb_free_vmemmap=on,
prep_and_add_bootmem_folios() can access pageblock flags on bootmem
HugeTLB pages whose mirrored tail struct pages already point to the shared
tail page. On CONFIG_DEBUG_VM kernels, get_pfnblock_bitmap_bitidx() then
dereferences the still-uninitialized shared tail page and can panic during
boot.
Initialize zone->vmemmap_tails[] from gather_bootmem_prealloc(), before
bootmem HugeTLB folios are processed, and drop the later initialization
from hugetlb_vmemmap_init().
This bug only affects CONFIG_DEBUG_VM kernels, where the relevant
assertion is evaluated. |
| In the Linux kernel, the following vulnerability has been resolved:
lockd: fix swapped arguments in nlmsvc_match_ip()
When releasing locks by server IP address via /proc/fs/nfsd/unlock_ip,
nlmsvc_unlock_all_by_ip() calls nlm_traverse_files() with the server
sockaddr as the opaque @data argument:
nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL);
The match callback is later invoked from nlm_traverse_locks() as:
match(lockhost, host);
where the first argument is the nlm_host that owns the lock, and the
second argument is the @data that was originally passed down (here the
server sockaddr). This is the convention every other match callback
relies on (nlmsvc_mark_host(), nlmsvc_same_host(), nlmsvc_is_client()):
arg1 is the real nlm_host, arg2 is the caller-supplied reference value.
nlmsvc_match_ip() has had these two arguments reversed ever since the
unlock-by-IP feature was introduced in commit 4373ea84c84d ("lockd:
unlock lockd locks associated with a given server ip"):
return rpc_cmp_addr(nlm_srcaddr(host), datap);
Here @host is actually the server sockaddr, so nlm_srcaddr(host)
dereferences a struct sockaddr as a struct nlm_host and reads garbage
at the offset of h_srcaddr; meanwhile @datap is actually the lock
owner's nlm_host but is compared as a sockaddr. As a result the
comparison practically never matches and locks are not released for the
requested IP.
Swap the arguments so the lock owner's source address is compared
against the requested server address:
return rpc_cmp_addr(nlm_srcaddr(datap), (struct sockaddr *)host);
[ cel: fix the misleading typedef parameter names too ] |
| In the Linux kernel, the following vulnerability has been resolved:
mm/hugetlb: initialize gigantic bootmem hugepage struct pages earlier
Gigantic bootmem HugeTLB pages are currently initialized from
hugetlb_init(), but page_alloc_init_late() runs earlier and walks
pageblocks to determine zone contiguity.
If a bootmem HugeTLB region is marked noinit, set_zone_contiguous() can
observe still-uninitialized struct pages through
__pageblock_pfn_to_page(). This may not trigger an immediate failure, but
it can make set_zone_contiguous() compute the wrong zone contiguity state.
If extra poisoned-page checks are added in this path, such as
PF_POISONED_CHECK() in page_zone_id(), it can also trigger an early boot
panic.
Initialize gigantic bootmem HugeTLB struct pages from
page_alloc_init_late(), before zone contiguity is evaluated, so later page
allocator setup only sees valid struct page state. This also makes the
initialization order more natural, as struct pages should be initialized
before later code inspects them. |
| In the Linux kernel, the following vulnerability has been resolved:
nfsd: add missing read barrier to rpc_status_get dumpit seqcount retry
The hand-rolled seqcount-like protocol in nfsd_nl_rpc_status_get_dumpit()
is missing a read memory barrier (smp_rmb) before its second counter
check. The standard kernel read_seqcount_retry() includes smp_rmb()
to ensure that all data reads complete before the counter is re-checked.
Without this barrier, on weakly-ordered architectures (ARM, POWER),
the CPU may reorder field reads past the second counter check, making
the retry logic ineffective: it could observe a consistent counter pair
while reading fields that have been concurrently modified by the writer.
Add smp_rmb() before the second counter check to order the field reads
ahead of it, matching the barrier semantics of the standard seqcount
read-side. The begin-side smp_load_acquire() already pairs with the
smp_store_release() in nfsd_dispatch(); with the smp_rmb() now ordering
the field reads, the retry check no longer needs acquire semantics and
reads the counter with a plain READ_ONCE(), as read_seqcount_retry()
does.
[ cel: Use READ_ONCE instead of smp_load_acquire() ] |
| In the Linux kernel, the following vulnerability has been resolved:
svcrdma: Reject Write/Reply chunks with segcount 0
A peer can send a Write or Reply chunk whose segcount field is zero.
xdr_check_write_chunk() only rejects segcount > rc_maxpages, so zero
passes the range check, and xdr_inline_decode(stream, 0) returns the
current (non-NULL) cursor without advancing. The function returns
true and pcl_alloc_write() then links a struct svc_rdma_chunk with
ch_segcount == 0 onto rc_write_pcl or rc_reply_pcl.
An earlier patch in this series made pcl_for_each_segment() safe for
ch_segcount == 0, so this no longer drives the memory walk it used
to. Rejecting the malformed frame at the decode boundary is still
worthwhile as defense in depth: it keeps degenerate zero-segment
chunks off the parsed chunk lists entirely, so any future consumer
that walks ch_segments directly cannot observe one, and it makes the
zero-floor easy to backport to trees where the macro change is more
intrusive. RFC 8166 has no meaning for a Write/Reply chunk that
describes no remote buffer, so no legitimate client is affected.
xdr_check_reply_chunk() funnels Reply chunks through
xdr_check_write_chunk() and inherits the same rejection.
pcl_alloc_write() also links each chunk onto the parsed chunk list
before filling its segment array. If a future change weakens the
segcount-0 rejection, an incomplete chunk is visible to consumers
during the fill loop. Reorder so that list_add_tail() follows the
segment fill loop, ensuring only fully-populated chunks appear on
the list. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/mm_init: deferred_grow_zone(): fix out-of-range first_deferred_pfn
With CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled, deferred_grow_zone()
initializes struct pages early in boot to satisfy an allocation.
With a large CMA reservation in place, the ranges deferred_init_memmap()
finds may not add up to the allocation it was asked for, and the function
ends up initializing the memory map of the entire zone and still falls
short.
That is fine in itself: the function accounts for it and leaves the
caller to decide whether it now has enough memory.
However, the update of pgdat->first_deferred_pfn that tracks where
uninitialized memory map starts could overflow.
If the node's RAM end is not aligned on PAGES_PER_SECTION boundaries and
some deferred struct pages were initialized, pgdat->first_deferred_pfn
would point past the end of the node's memory.
deferred_init_memmap() later picks up from pgdat->first_deferred_pfn and
hits a BUG_ON(), because it expects a pfn within its node.
For example, when running a kernel with CONFIG_DEFERRED_STRUCT_PAGE_INIT=y
and CONFIG_CMA=y using the following qemu command line
qemu-system-x86_64 -enable-kvm -m 8032M -kernel bzImage \
-append "nokaslr cma=4768M@0x100000000"
the kernel panics:
kernel BUG at mm/mm_init.c:2131!
CPU: 3 UID: 0 PID: 36 Comm: pgdatinit0 Not tainted 7.2.0-rc6 #1
RIP: 0010:deferred_init_memmap+0x1b8/0x1c0
RAX: 0000000000236000 R13: 0000000000238000
Call Trace:
kthread+0xdf/0x120
ret_from_fork+0x187/0x250
Make sure that the update of pgdta->first_deferred_pfn does not overflow
when the entire zone's (and therefore node's) memory map is initialized.
[rppt: massaged the changelog] |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: use RCU iterator to dump route exceptions
rt6_nh_dump_exceptions() uses hlist_for_each_entry() to iterate over
RCU-protected exception lists. The caller holds rcu_read_lock(), but does
not hold rt6_exception_lock, so rt6_insert_exception() can concurrently
add an entry with hlist_add_head_rcu().
KCSAN reports this race (irrelevant details omitted):
==================================================================
BUG: KCSAN: data-race in rt6_insert_exception / rt6_nh_dump_exceptions
write (marked) to 0xffff8a7c44c59620 of 8 bytes by interrupt on cpu 5:
rt6_insert_exception+0x3bb/0x760
__ip6_rt_update_pmtu+0x4fe/0x750
ip6_sk_update_pmtu+0x19a/0x3b0
udpv6_err+0x3ff/0x800
icmpv6_notify+0x1e1/0x440
icmpv6_rcv+0x8c0/0xab0
ip6_protocol_deliver_rcu+0x616/0x840
ip6_input_finish+0xb9/0x160
...
entry_SYSCALL_64_after_hwframe+0x77/0x7f
read to 0xffff8a7c44c59620 of 8 bytes by task 549 on cpu 14:
rt6_nh_dump_exceptions+0xb3/0x260
rt6_dump_route+0x53e/0x5f0
fib6_dump_node+0x6d/0xf0
fib6_walk_continue+0x290/0x2d0
fib6_dump_table+0x28d/0x360
inet6_dump_fib+0x37d/0x620
rtnl_dumpit+0x7b/0xd0
netlink_dump+0x3ae/0x7e0
...
entry_SYSCALL_64_after_hwframe+0x77/0x7f
4 locks held by dumper/549:
...
#1: (rcu_read_lock){....}-{1:3}, at: inet6_dump_fib+0x88/0x620
#2: (&tb->tb6_lock){+.-.}-{3:3}, at: fib6_dump_table+0x1e9/0x360
#3: (rcu_read_lock){....}-{1:3}, at: rt6_dump_route+0x483/0x5f0
value changed: 0xffff8a7c44e05700 -> 0xffff8a7c45d60100
Reported by Kernel Concurrency Sanitizer on:
CPU: 14 UID: 0 PID: 549 Comm: dumper Not tainted
7.2.0-rc7-virtme #38 PREEMPT(lazy)
...
Use hlist_for_each_entry_rcu() to safely iterate over the exception list. |
| In the Linux kernel, the following vulnerability has been resolved:
phy: fsl-imx8mq-usb: fix typec switch leak on probe error path
If probe fails after imx95_usb_phy_get_tca() succeeds, the typec
switch leaks because the only cleanup path was in .remove(), which
never runs on probe failure.
Use devm_add_action_or_reset() so the switch is cleaned up on both
probe failure and driver removal. The imx95_usb_phy_put_tca() is no
longer needed, it will be removed in .remove() too. |
| In the Linux kernel, the following vulnerability has been resolved:
svcrdma: Fix unmatched rn_unregister on failed accept
When svc_rdma_accept() takes the errout path before
rpcrdma_rn_register() has succeeded, the existing cleanup block
calls rpcrdma_rn_unregister(dev, &newxprt->sc_rn) unconditionally.
svcxprt_rdma is kzalloc'd, so on that path sc_rn.rn_index is 0 and
sc_rn.rn_done is NULL; the unregister therefore xa_erase()s another
caller's slot 0 and performs an unmatched kref_put() on the
rpcrdma_device's rd_kref.
The same errout also brackets the cleanup with svc_xprt_get()/
svc_xprt_put() around the kref_init() birth reference. The kref
goes 1 -> 2 -> 1 and never reaches 0, so the svcxprt_rdma (and the
net/ns_tracker it pinned) is leaked on every failed accept.
rpcrdma_rn_register() writes rn->rn_done last, only after xa_alloc()
and kref_get() have both succeeded, so rn_done == NULL is a natural
"never registered" sentinel. Guard rpcrdma_rn_unregister() with an
early return when rn_done is NULL, and clear rn_done before the
matching xa_erase() so a repeated unregister is also a no-op.
With that guard in place, the accept errout drops the kref_init()
birth reference via svc_xprt_put(), which dispatches svc_rdma_free().
Teardown of sc_qp, sc_sq_cq, sc_rq_cq, and sc_pd runs under existing
IS_ERR/NULL guards in svc_rdma_free(); sc_rn is covered by the new
rn_done sentinel; sc_cm_id is non-NULL on every errout path because
svc_rdma_accept() dereferences it above the first goto errout.
svc_xprt_free() drops the module reference associated with the freed
transport, and svc_handle_xprt() drops its pre-acquired reference
when ->xpo_accept() returns NULL. Take a replacement module reference
before svc_xprt_put() so the two module_put()s remain balanced.
The rn_done guard also covers svc_rdma_free()'s non-listener call
to rpcrdma_rn_unregister() for transports whose register attempt
failed or never ran. |
| In the Linux kernel, the following vulnerability has been resolved:
staging: media: tegra-video: fix of_node_put() on VIP parse errors
tegra_vip_channel_of_parse() initializes np from dev->of_node without
taking a reference, but its error paths drop one through the
err_node_put label. This underflows the refcount of the VIP device's
OF node when endpoint parsing fails on a malformed device tree.
The only reference the function takes on np is the success-path
of_node_get() stored in vip->chan.of_node, and that one is already
released by the tegra_vip_init() error path and by tegra_vip_exit().
Return errors directly instead of jumping to the bogus cleanup label. |
| In the Linux kernel, the following vulnerability has been resolved:
signal: avoid shared siginfo namespace rewrites
send_signal_locked() rewrites sender ids for the target namespace. Group
sends reuse the same siginfo, so one recipient can affect the next.
Copy the siginfo before changing it. |
| In the Linux kernel, the following vulnerability has been resolved:
nfsd: convert nfsd_net boolean flags to unsigned long flags word
nfsd_net contains several boolean fields that are accessed from
concurrent contexts without serialization. In particular,
nfsd4_end_grace() guards its drain path with a plain bool:
if (nn->grace_ended)
return;
nn->grace_ended = true;
The read and the write are independent, and nothing in struct
nfsd_net serializes them. At least two contexts can reach this
code with no lock held:
laundromat path
laundry_wq kworker
nfs4_laundromat()
nfsd4_end_grace()
RECLAIM_COMPLETE path
nfsd compound kthread
nfsd4_reclaim_complete()
inc_reclaim_complete()
nfsd4_end_grace()
Both callers can observe grace_ended == false on different CPUs,
both store true, and both proceed into nfsd4_record_grace_done(),
which invokes the active client_tracking_ops->grace_done callback.
For tracking ops that drain reclaim_str_hashtbl (legacy_tracking_ops
via nfsd4_recdir_purge_old, and the cld v1+ ops via
nfsd4_cld_grace_done), grace_done calls nfs4_release_reclaim(),
which walks every bucket of reclaim_str_hashtbl with no lock and
calls nfs4_remove_reclaim_record() (list_del + kfree) on each
entry. Two concurrent walkers corrupt the list and double-free
every nfs4_client_reclaim. A concurrent nfsd4_find_reclaim_client()
iterating the same bucket reads through freed memory.
A third call site exists in nfs4_state_start_net() on the
skip_grace startup path, but it runs under nfsd_mutex before any
client has connected and before the laundromat's first delayed
work fires, so it cannot race with the two callers above.
Replace the scattered boolean fields in nfsd_net with a single
unsigned long flags word and an enum nfsd_net_flag for the bit
positions. The grace_ended race is fixed by using
test_and_set_bit(), which is atomic on all architectures. The
remaining flags (grace_end_forced, in_grace, somebody_reclaimed,
track_reclaim_completes, nfsd_net_up, lockd_up) are converted to
use test_bit/set_bit/clear_bit for consistency. This avoids
sub-word cmpxchg issues on architectures like Hexagon that only
support word-sized atomic operations. |
| In the Linux kernel, the following vulnerability has been resolved:
sched_ext: Keep kick_sync waiting on the rq's own CPU
kick_sync_wait_bal_cb() assumes it runs on the rq's CPU from the
__schedule() tail: the snapshots it compares against live in that CPU's
percpu area and the busy-wait runs with the rq lock dropped and IRQs
enabled.
However, dispatch can now drop the rq lock while the callback sits queued,
and rq lock takers in that window (the sched class change paths, the scx
task iterator) flush pending balance callbacks on release, running the
callback on a foreign CPU. Such a run compares against unrelated snapshots
and can deadlock when the executing CPU is itself a wait target.
Bail on a foreign CPU and leave the wait state alone. The wait only observes
progress that the resched kicks already guarantee and the rq's next wait
picks up the stale cpus_to_sync bits. |
