Security Vulnerabilities - CVEs Published In June 2025
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix space cache corruption and potential double allocations
When testing space_cache v2 on a large set of machines, we encountered a
few symptoms:
1. "unable to add free space :-17" (EEXIST) errors.
2. Missing free space info items, sometimes caught with a "missing free
space info for X" error.
3. Double-accounted space: ranges that were allocated in the extent tree
and also marked as free in the free space tree, ranges that were
marked as allocated twice in the extent tree, or ranges that were
marked as free twice in the free space tree. If the latter made it
onto disk, the next reboot would hit the BUG_ON() in
add_new_free_space().
4. On some hosts with no on-disk corruption or error messages, the
in-memory space cache (dumped with drgn) disagreed with the free
space tree.
All of these symptoms have the same underlying cause: a race between
caching the free space for a block group and returning free space to the
in-memory space cache for pinned extents causes us to double-add a free
range to the space cache. This race exists when free space is cached
from the free space tree (space_cache=v2) or the extent tree
(nospace_cache, or space_cache=v1 if the cache needs to be regenerated).
struct btrfs_block_group::last_byte_to_unpin and struct
btrfs_block_group::progress are supposed to protect against this race,
but commit d0c2f4fa555e ("btrfs: make concurrent fsyncs wait less when
waiting for a transaction commit") subtly broke this by allowing
multiple transactions to be unpinning extents at the same time.
Specifically, the race is as follows:
1. An extent is deleted from an uncached block group in transaction A.
2. btrfs_commit_transaction() is called for transaction A.
3. btrfs_run_delayed_refs() -> __btrfs_free_extent() runs the delayed
ref for the deleted extent.
4. __btrfs_free_extent() -> do_free_extent_accounting() ->
add_to_free_space_tree() adds the deleted extent back to the free
space tree.
5. do_free_extent_accounting() -> btrfs_update_block_group() ->
btrfs_cache_block_group() queues up the block group to get cached.
block_group->progress is set to block_group->start.
6. btrfs_commit_transaction() for transaction A calls
switch_commit_roots(). It sets block_group->last_byte_to_unpin to
block_group->progress, which is block_group->start because the block
group hasn't been cached yet.
7. The caching thread gets to our block group. Since the commit roots
were already switched, load_free_space_tree() sees the deleted extent
as free and adds it to the space cache. It finishes caching and sets
block_group->progress to U64_MAX.
8. btrfs_commit_transaction() advances transaction A to
TRANS_STATE_SUPER_COMMITTED.
9. fsync calls btrfs_commit_transaction() for transaction B. Since
transaction A is already in TRANS_STATE_SUPER_COMMITTED and the
commit is for fsync, it advances.
10. btrfs_commit_transaction() for transaction B calls
switch_commit_roots(). This time, the block group has already been
cached, so it sets block_group->last_byte_to_unpin to U64_MAX.
11. btrfs_commit_transaction() for transaction A calls
btrfs_finish_extent_commit(), which calls unpin_extent_range() for
the deleted extent. It sees last_byte_to_unpin set to U64_MAX (by
transaction B!), so it adds the deleted extent to the space cache
again!
This explains all of our symptoms above:
* If the sequence of events is exactly as described above, when the free
space is re-added in step 11, it will fail with EEXIST.
* If another thread reallocates the deleted extent in between steps 7
and 11, then step 11 will silently re-add that space to the space
cache as free even though it is actually allocated. Then, if that
space is allocated *again*, the free space tree will be corrupted
(namely, the wrong item will be deleted).
* If we don't catch this free space tree corr
---truncated---
CVSS Score
7.8
EPSS Score
0.001
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
netfilter: flowtable: fix stuck flows on cleanup due to pending work
To clear the flow table on flow table free, the following sequence
normally happens in order:
1) gc_step work is stopped to disable any further stats/del requests.
2) All flow table entries are set to teardown state.
3) Run gc_step which will queue HW del work for each flow table entry.
4) Waiting for the above del work to finish (flush).
5) Run gc_step again, deleting all entries from the flow table.
6) Flow table is freed.
But if a flow table entry already has pending HW stats or HW add work
step 3 will not queue HW del work (it will be skipped), step 4 will wait
for the pending add/stats to finish, and step 5 will queue HW del work
which might execute after freeing of the flow table.
To fix the above, this patch flushes the pending work, then it sets the
teardown flag to all flows in the flowtable and it forces a garbage
collector run to queue work to remove the flows from hardware, then it
flushes this new pending work and (finally) it forces another garbage
collector run to remove the entry from the software flowtable.
Stack trace:
[47773.882335] BUG: KASAN: use-after-free in down_read+0x99/0x460
[47773.883634] Write of size 8 at addr ffff888103b45aa8 by task kworker/u20:6/543704
[47773.885634] CPU: 3 PID: 543704 Comm: kworker/u20:6 Not tainted 5.12.0-rc7+ #2
[47773.886745] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009)
[47773.888438] Workqueue: nf_ft_offload_del flow_offload_work_handler [nf_flow_table]
[47773.889727] Call Trace:
[47773.890214] dump_stack+0xbb/0x107
[47773.890818] print_address_description.constprop.0+0x18/0x140
[47773.892990] kasan_report.cold+0x7c/0xd8
[47773.894459] kasan_check_range+0x145/0x1a0
[47773.895174] down_read+0x99/0x460
[47773.899706] nf_flow_offload_tuple+0x24f/0x3c0 [nf_flow_table]
[47773.907137] flow_offload_work_handler+0x72d/0xbe0 [nf_flow_table]
[47773.913372] process_one_work+0x8ac/0x14e0
[47773.921325]
[47773.921325] Allocated by task 592159:
[47773.922031] kasan_save_stack+0x1b/0x40
[47773.922730] __kasan_kmalloc+0x7a/0x90
[47773.923411] tcf_ct_flow_table_get+0x3cb/0x1230 [act_ct]
[47773.924363] tcf_ct_init+0x71c/0x1156 [act_ct]
[47773.925207] tcf_action_init_1+0x45b/0x700
[47773.925987] tcf_action_init+0x453/0x6b0
[47773.926692] tcf_exts_validate+0x3d0/0x600
[47773.927419] fl_change+0x757/0x4a51 [cls_flower]
[47773.928227] tc_new_tfilter+0x89a/0x2070
[47773.936652]
[47773.936652] Freed by task 543704:
[47773.937303] kasan_save_stack+0x1b/0x40
[47773.938039] kasan_set_track+0x1c/0x30
[47773.938731] kasan_set_free_info+0x20/0x30
[47773.939467] __kasan_slab_free+0xe7/0x120
[47773.940194] slab_free_freelist_hook+0x86/0x190
[47773.941038] kfree+0xce/0x3a0
[47773.941644] tcf_ct_flow_table_cleanup_work
Original patch description and stack trace by Paul Blakey.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_tproxy: restrict to prerouting hook
TPROXY is only allowed from prerouting, but nft_tproxy doesn't check this.
This fixes a crash (null dereference) when using tproxy from e.g. output.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
bpf: Don't use tnum_range on array range checking for poke descriptors
Hsin-Wei reported a KASAN splat triggered by their BPF runtime fuzzer which
is based on a customized syzkaller:
BUG: KASAN: slab-out-of-bounds in bpf_int_jit_compile+0x1257/0x13f0
Read of size 8 at addr ffff888004e90b58 by task syz-executor.0/1489
CPU: 1 PID: 1489 Comm: syz-executor.0 Not tainted 5.19.0 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x9c/0xc9
print_address_description.constprop.0+0x1f/0x1f0
? bpf_int_jit_compile+0x1257/0x13f0
kasan_report.cold+0xeb/0x197
? kvmalloc_node+0x170/0x200
? bpf_int_jit_compile+0x1257/0x13f0
bpf_int_jit_compile+0x1257/0x13f0
? arch_prepare_bpf_dispatcher+0xd0/0xd0
? rcu_read_lock_sched_held+0x43/0x70
bpf_prog_select_runtime+0x3e8/0x640
? bpf_obj_name_cpy+0x149/0x1b0
bpf_prog_load+0x102f/0x2220
? __bpf_prog_put.constprop.0+0x220/0x220
? find_held_lock+0x2c/0x110
? __might_fault+0xd6/0x180
? lock_downgrade+0x6e0/0x6e0
? lock_is_held_type+0xa6/0x120
? __might_fault+0x147/0x180
__sys_bpf+0x137b/0x6070
? bpf_perf_link_attach+0x530/0x530
? new_sync_read+0x600/0x600
? __fget_files+0x255/0x450
? lock_downgrade+0x6e0/0x6e0
? fput+0x30/0x1a0
? ksys_write+0x1a8/0x260
__x64_sys_bpf+0x7a/0xc0
? syscall_enter_from_user_mode+0x21/0x70
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f917c4e2c2d
The problem here is that a range of tnum_range(0, map->max_entries - 1) has
limited ability to represent the concrete tight range with the tnum as the
set of resulting states from value + mask can result in a superset of the
actual intended range, and as such a tnum_in(range, reg->var_off) check may
yield true when it shouldn't, for example tnum_range(0, 2) would result in
00XX -> v = 0000, m = 0011 such that the intended set of {0, 1, 2} is here
represented by a less precise superset of {0, 1, 2, 3}. As the register is
known const scalar, really just use the concrete reg->var_off.value for the
upper index check.
CVSS Score
7.1
EPSS Score
0.001
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
scsi: storvsc: Remove WQ_MEM_RECLAIM from storvsc_error_wq
storvsc_error_wq workqueue should not be marked as WQ_MEM_RECLAIM as it
doesn't need to make forward progress under memory pressure. Marking this
workqueue as WQ_MEM_RECLAIM may cause deadlock while flushing a
non-WQ_MEM_RECLAIM workqueue. In the current state it causes the following
warning:
[ 14.506347] ------------[ cut here ]------------
[ 14.506354] workqueue: WQ_MEM_RECLAIM storvsc_error_wq_0:storvsc_remove_lun is flushing !WQ_MEM_RECLAIM events_freezable_power_:disk_events_workfn
[ 14.506360] WARNING: CPU: 0 PID: 8 at <-snip->kernel/workqueue.c:2623 check_flush_dependency+0xb5/0x130
[ 14.506390] CPU: 0 PID: 8 Comm: kworker/u4:0 Not tainted 5.4.0-1086-azure #91~18.04.1-Ubuntu
[ 14.506391] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 05/09/2022
[ 14.506393] Workqueue: storvsc_error_wq_0 storvsc_remove_lun
[ 14.506395] RIP: 0010:check_flush_dependency+0xb5/0x130
<-snip->
[ 14.506408] Call Trace:
[ 14.506412] __flush_work+0xf1/0x1c0
[ 14.506414] __cancel_work_timer+0x12f/0x1b0
[ 14.506417] ? kernfs_put+0xf0/0x190
[ 14.506418] cancel_delayed_work_sync+0x13/0x20
[ 14.506420] disk_block_events+0x78/0x80
[ 14.506421] del_gendisk+0x3d/0x2f0
[ 14.506423] sr_remove+0x28/0x70
[ 14.506427] device_release_driver_internal+0xef/0x1c0
[ 14.506428] device_release_driver+0x12/0x20
[ 14.506429] bus_remove_device+0xe1/0x150
[ 14.506431] device_del+0x167/0x380
[ 14.506432] __scsi_remove_device+0x11d/0x150
[ 14.506433] scsi_remove_device+0x26/0x40
[ 14.506434] storvsc_remove_lun+0x40/0x60
[ 14.506436] process_one_work+0x209/0x400
[ 14.506437] worker_thread+0x34/0x400
[ 14.506439] kthread+0x121/0x140
[ 14.506440] ? process_one_work+0x400/0x400
[ 14.506441] ? kthread_park+0x90/0x90
[ 14.506443] ret_from_fork+0x35/0x40
[ 14.506445] ---[ end trace 2d9633159fdc6ee7 ]---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
md: call __md_stop_writes in md_stop
From the link [1], we can see raid1d was running even after the path
raid_dtr -> md_stop -> __md_stop.
Let's stop write first in destructor to align with normal md-raid to
fix the KASAN issue.
[1]. https://lore.kernel.org/linux-raid/CAPhsuW5gc4AakdGNdF8ubpezAuDLFOYUO_sfMZcec6hQFm8nhg@mail.gmail.com/T/#m7f12bf90481c02c6d2da68c64aeed4779b7df74a
CVSS Score
5.5
EPSS Score
0.001
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
xen/privcmd: fix error exit of privcmd_ioctl_dm_op()
The error exit of privcmd_ioctl_dm_op() is calling unlock_pages()
potentially with pages being NULL, leading to a NULL dereference.
Additionally lock_pages() doesn't check for pin_user_pages_fast()
having been completely successful, resulting in potentially not
locking all pages into memory. This could result in sporadic failures
when using the related memory in user mode.
Fix all of that by calling unlock_pages() always with the real number
of pinned pages, which will be zero in case pages being NULL, and by
checking the number of pages pinned by pin_user_pages_fast() matching
the expected number of pages.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
s390: fix double free of GS and RI CBs on fork() failure
The pointers for guarded storage and runtime instrumentation control
blocks are stored in the thread_struct of the associated task. These
pointers are initially copied on fork() via arch_dup_task_struct()
and then cleared via copy_thread() before fork() returns. If fork()
happens to fail after the initial task dup and before copy_thread(),
the newly allocated task and associated thread_struct memory are
freed via free_task() -> arch_release_task_struct(). This results in
a double free of the guarded storage and runtime info structs
because the fields in the failed task still refer to memory
associated with the source task.
This problem can manifest as a BUG_ON() in set_freepointer() (with
CONFIG_SLAB_FREELIST_HARDENED enabled) or KASAN splat (if enabled)
when running trinity syscall fuzz tests on s390x. To avoid this
problem, clear the associated pointer fields in
arch_dup_task_struct() immediately after the new task is copied.
Note that the RI flag is still cleared in copy_thread() because it
resides in thread stack memory and that is where stack info is
copied.
CVSS Score
7.8
EPSS Score
0.001
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
mm/hugetlb: avoid corrupting page->mapping in hugetlb_mcopy_atomic_pte
In MCOPY_ATOMIC_CONTINUE case with a non-shared VMA, pages in the page
cache are installed in the ptes. But hugepage_add_new_anon_rmap is called
for them mistakenly because they're not vm_shared. This will corrupt the
page->mapping used by page cache code.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-06-18
In the Linux kernel, the following vulnerability has been resolved:
mm/mprotect: only reference swap pfn page if type match
Yu Zhao reported a bug after the commit "mm/swap: Add swp_offset_pfn() to
fetch PFN from swap entry" added a check in swp_offset_pfn() for swap type [1]:
kernel BUG at include/linux/swapops.h:117!
CPU: 46 PID: 5245 Comm: EventManager_De Tainted: G S O L 6.0.0-dbg-DEV #2
RIP: 0010:pfn_swap_entry_to_page+0x72/0xf0
Code: c6 48 8b 36 48 83 fe ff 74 53 48 01 d1 48 83 c1 08 48 8b 09 f6
c1 01 75 7b 66 90 48 89 c1 48 8b 09 f6 c1 01 74 74 5d c3 eb 9e <0f> 0b
48 ba ff ff ff ff 03 00 00 00 eb ae a9 ff 0f 00 00 75 13 48
RSP: 0018:ffffa59e73fabb80 EFLAGS: 00010282
RAX: 00000000ffffffe8 RBX: 0c00000000000000 RCX: ffffcd5440000000
RDX: 1ffffffffff7a80a RSI: 0000000000000000 RDI: 0c0000000000042b
RBP: ffffa59e73fabb80 R08: ffff9965ca6e8bb8 R09: 0000000000000000
R10: ffffffffa5a2f62d R11: 0000030b372e9fff R12: ffff997b79db5738
R13: 000000000000042b R14: 0c0000000000042b R15: 1ffffffffff7a80a
FS: 00007f549d1bb700(0000) GS:ffff99d3cf680000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000440d035b3180 CR3: 0000002243176004 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
change_pte_range+0x36e/0x880
change_p4d_range+0x2e8/0x670
change_protection_range+0x14e/0x2c0
mprotect_fixup+0x1ee/0x330
do_mprotect_pkey+0x34c/0x440
__x64_sys_mprotect+0x1d/0x30
It triggers because pfn_swap_entry_to_page() could be called upon e.g. a
genuine swap entry.
Fix it by only calling it when it's a write migration entry where the page*
is used.
[1] https://lore.kernel.org/lkml/CAOUHufaVC2Za-p8m0aiHw6YkheDcrO-C3wRGixwDS32VTS+k1w@mail.gmail.com/
CVSS Score
5.5
EPSS Score
0.001
Published
2025-06-18