| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
s390/dasd: fix error recovery leading to data corruption on ESE devices
Extent Space Efficient (ESE) or thin provisioned volumes need to be
formatted on demand during usual IO processing.
The dasd_ese_needs_format function checks for error codes that signal
the non existence of a proper track format.
The check for incorrect length is to imprecise since other error cases
leading to transport of insufficient data also have this flag set.
This might lead to data corruption in certain error cases for example
during a storage server warmstart.
Fix by removing the check for incorrect length and replacing by
explicitly checking for invalid track format in transport mode.
Also remove the check for file protected since this is not a valid
ESE handling case. |
| In the Linux kernel, the following vulnerability has been resolved:
fix bitmap corruption on close_range() with CLOSE_RANGE_UNSHARE
copy_fd_bitmaps(new, old, count) is expected to copy the first
count/BITS_PER_LONG bits from old->full_fds_bits[] and fill
the rest with zeroes. What it does is copying enough words
(BITS_TO_LONGS(count/BITS_PER_LONG)), then memsets the rest.
That works fine, *if* all bits past the cutoff point are
clear. Otherwise we are risking garbage from the last word
we'd copied.
For most of the callers that is true - expand_fdtable() has
count equal to old->max_fds, so there's no open descriptors
past count, let alone fully occupied words in ->open_fds[],
which is what bits in ->full_fds_bits[] correspond to.
The other caller (dup_fd()) passes sane_fdtable_size(old_fdt, max_fds),
which is the smallest multiple of BITS_PER_LONG that covers all
opened descriptors below max_fds. In the common case (copying on
fork()) max_fds is ~0U, so all opened descriptors will be below
it and we are fine, by the same reasons why the call in expand_fdtable()
is safe.
Unfortunately, there is a case where max_fds is less than that
and where we might, indeed, end up with junk in ->full_fds_bits[] -
close_range(from, to, CLOSE_RANGE_UNSHARE) with
* descriptor table being currently shared
* 'to' being above the current capacity of descriptor table
* 'from' being just under some chunk of opened descriptors.
In that case we end up with observably wrong behaviour - e.g. spawn
a child with CLONE_FILES, get all descriptors in range 0..127 open,
then close_range(64, ~0U, CLOSE_RANGE_UNSHARE) and watch dup(0) ending
up with descriptor #128, despite #64 being observably not open.
The minimally invasive fix would be to deal with that in dup_fd().
If this proves to add measurable overhead, we can go that way, but
let's try to fix copy_fd_bitmaps() first.
* new helper: bitmap_copy_and_expand(to, from, bits_to_copy, size).
* make copy_fd_bitmaps() take the bitmap size in words, rather than
bits; it's 'count' argument is always a multiple of BITS_PER_LONG,
so we are not losing any information, and that way we can use the
same helper for all three bitmaps - compiler will see that count
is a multiple of BITS_PER_LONG for the large ones, so it'll generate
plain memcpy()+memset().
Reproducer added to tools/testing/selftests/core/close_range_test.c |
| In the Linux kernel, the following vulnerability has been resolved:
mm/vmalloc: fix page mapping if vm_area_alloc_pages() with high order fallback to order 0
The __vmap_pages_range_noflush() assumes its argument pages** contains
pages with the same page shift. However, since commit e9c3cda4d86e ("mm,
vmalloc: fix high order __GFP_NOFAIL allocations"), if gfp_flags includes
__GFP_NOFAIL with high order in vm_area_alloc_pages() and page allocation
failed for high order, the pages** may contain two different page shifts
(high order and order-0). This could lead __vmap_pages_range_noflush() to
perform incorrect mappings, potentially resulting in memory corruption.
Users might encounter this as follows (vmap_allow_huge = true, 2M is for
PMD_SIZE):
kvmalloc(2M, __GFP_NOFAIL|GFP_X)
__vmalloc_node_range_noprof(vm_flags=VM_ALLOW_HUGE_VMAP)
vm_area_alloc_pages(order=9) ---> order-9 allocation failed and fallback to order-0
vmap_pages_range()
vmap_pages_range_noflush()
__vmap_pages_range_noflush(page_shift = 21) ----> wrong mapping happens
We can remove the fallback code because if a high-order allocation fails,
__vmalloc_node_range_noprof() will retry with order-0. Therefore, it is
unnecessary to fallback to order-0 here. Therefore, fix this by removing
the fallback code. |
| In the Linux kernel, the following vulnerability has been resolved:
memcg_write_event_control(): fix a user-triggerable oops
we are *not* guaranteed that anything past the terminating NUL
is mapped (let alone initialized with anything sane). |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Take state lock during tx timeout reporter
mlx5e_safe_reopen_channels() requires the state lock taken. The
referenced changed in the Fixes tag removed the lock to fix another
issue. This patch adds it back but at a later point (when calling
mlx5e_safe_reopen_channels()) to avoid the deadlock referenced in the
Fixes tag. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: flowtable: initialise extack before use
Fix missing initialisation of extack in flow offload. |
| In the Linux kernel, the following vulnerability has been resolved:
netem: fix return value if duplicate enqueue fails
There is a bug in netem_enqueue() introduced by
commit 5845f706388a ("net: netem: fix skb length BUG_ON in __skb_to_sgvec")
that can lead to a use-after-free.
This commit made netem_enqueue() always return NET_XMIT_SUCCESS
when a packet is duplicated, which can cause the parent qdisc's q.qlen
to be mistakenly incremented. When this happens qlen_notify() may be
skipped on the parent during destruction, leaving a dangling pointer
for some classful qdiscs like DRR.
There are two ways for the bug happen:
- If the duplicated packet is dropped by rootq->enqueue() and then
the original packet is also dropped.
- If rootq->enqueue() sends the duplicated packet to a different qdisc
and the original packet is dropped.
In both cases NET_XMIT_SUCCESS is returned even though no packets
are enqueued at the netem qdisc.
The fix is to defer the enqueue of the duplicate packet until after
the original packet has been guaranteed to return NET_XMIT_SUCCESS. |
| In the Linux kernel, the following vulnerability has been resolved:
char: xillybus: Check USB endpoints when probing device
Ensure, as the driver probes the device, that all endpoints that the
driver may attempt to access exist and are of the correct type.
All XillyUSB devices must have a Bulk IN and Bulk OUT endpoint at
address 1. This is verified in xillyusb_setup_base_eps().
On top of that, a XillyUSB device may have additional Bulk OUT
endpoints. The information about these endpoints' addresses is deduced
from a data structure (the IDT) that the driver fetches from the device
while probing it. These endpoints are checked in setup_channels().
A XillyUSB device never has more than one IN endpoint, as all data
towards the host is multiplexed in this single Bulk IN endpoint. This is
why setup_channels() only checks OUT endpoints. |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: pm: only mark 'subflow' endp as available
Adding the following warning ...
WARN_ON_ONCE(msk->pm.local_addr_used == 0)
... before decrementing the local_addr_used counter helped to find a bug
when running the "remove single address" subtest from the mptcp_join.sh
selftests.
Removing a 'signal' endpoint will trigger the removal of all subflows
linked to this endpoint via mptcp_pm_nl_rm_addr_or_subflow() with
rm_type == MPTCP_MIB_RMSUBFLOW. This will decrement the local_addr_used
counter, which is wrong in this case because this counter is linked to
'subflow' endpoints, and here it is a 'signal' endpoint that is being
removed.
Now, the counter is decremented, only if the ID is being used outside
of mptcp_pm_nl_rm_addr_or_subflow(), only for 'subflow' endpoints, and
if the ID is not 0 -- local_addr_used is not taking into account these
ones. This marking of the ID as being available, and the decrement is
done no matter if a subflow using this ID is currently available,
because the subflow could have been closed before. |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: pm: only decrement add_addr_accepted for MPJ req
Adding the following warning ...
WARN_ON_ONCE(msk->pm.add_addr_accepted == 0)
... before decrementing the add_addr_accepted counter helped to find a
bug when running the "remove single subflow" subtest from the
mptcp_join.sh selftest.
Removing a 'subflow' endpoint will first trigger a RM_ADDR, then the
subflow closure. Before this patch, and upon the reception of the
RM_ADDR, the other peer will then try to decrement this
add_addr_accepted. That's not correct because the attached subflows have
not been created upon the reception of an ADD_ADDR.
A way to solve that is to decrement the counter only if the attached
subflow was an MP_JOIN to a remote id that was not 0, and initiated by
the host receiving the RM_ADDR. |
| In the Linux kernel, the following vulnerability has been resolved:
char: xillybus: Don't destroy workqueue from work item running on it
Triggered by a kref decrement, destroy_workqueue() may be called from
within a work item for destroying its own workqueue. This illegal
situation is averted by adding a module-global workqueue for exclusive
use of the offending work item. Other work items continue to be queued
on per-device workqueues to ensure performance. |
| In the Linux kernel, the following vulnerability has been resolved:
xhci: Fix Panther point NULL pointer deref at full-speed re-enumeration
re-enumerating full-speed devices after a failed address device command
can trigger a NULL pointer dereference.
Full-speed devices may need to reconfigure the endpoint 0 Max Packet Size
value during enumeration. Usb core calls usb_ep0_reinit() in this case,
which ends up calling xhci_configure_endpoint().
On Panther point xHC the xhci_configure_endpoint() function will
additionally check and reserve bandwidth in software. Other hosts do
this in hardware
If xHC address device command fails then a new xhci_virt_device structure
is allocated as part of re-enabling the slot, but the bandwidth table
pointers are not set up properly here.
This triggers the NULL pointer dereference the next time usb_ep0_reinit()
is called and xhci_configure_endpoint() tries to check and reserve
bandwidth
[46710.713538] usb 3-1: new full-speed USB device number 5 using xhci_hcd
[46710.713699] usb 3-1: Device not responding to setup address.
[46710.917684] usb 3-1: Device not responding to setup address.
[46711.125536] usb 3-1: device not accepting address 5, error -71
[46711.125594] BUG: kernel NULL pointer dereference, address: 0000000000000008
[46711.125600] #PF: supervisor read access in kernel mode
[46711.125603] #PF: error_code(0x0000) - not-present page
[46711.125606] PGD 0 P4D 0
[46711.125610] Oops: Oops: 0000 [#1] PREEMPT SMP PTI
[46711.125615] CPU: 1 PID: 25760 Comm: kworker/1:2 Not tainted 6.10.3_2 #1
[46711.125620] Hardware name: Gigabyte Technology Co., Ltd.
[46711.125623] Workqueue: usb_hub_wq hub_event [usbcore]
[46711.125668] RIP: 0010:xhci_reserve_bandwidth (drivers/usb/host/xhci.c
Fix this by making sure bandwidth table pointers are set up correctly
after a failed address device command, and additionally by avoiding
checking for bandwidth in cases like this where no actual endpoints are
added or removed, i.e. only context for default control endpoint 0 is
evaluated. |
| In the Linux kernel, the following vulnerability has been resolved:
vfs: Don't evict inode under the inode lru traversing context
The inode reclaiming process(See function prune_icache_sb) collects all
reclaimable inodes and mark them with I_FREEING flag at first, at that
time, other processes will be stuck if they try getting these inodes
(See function find_inode_fast), then the reclaiming process destroy the
inodes by function dispose_list(). Some filesystems(eg. ext4 with
ea_inode feature, ubifs with xattr) may do inode lookup in the inode
evicting callback function, if the inode lookup is operated under the
inode lru traversing context, deadlock problems may happen.
Case 1: In function ext4_evict_inode(), the ea inode lookup could happen
if ea_inode feature is enabled, the lookup process will be stuck
under the evicting context like this:
1. File A has inode i_reg and an ea inode i_ea
2. getfattr(A, xattr_buf) // i_ea is added into lru // lru->i_ea
3. Then, following three processes running like this:
PA PB
echo 2 > /proc/sys/vm/drop_caches
shrink_slab
prune_dcache_sb
// i_reg is added into lru, lru->i_ea->i_reg
prune_icache_sb
list_lru_walk_one
inode_lru_isolate
i_ea->i_state |= I_FREEING // set inode state
inode_lru_isolate
__iget(i_reg)
spin_unlock(&i_reg->i_lock)
spin_unlock(lru_lock)
rm file A
i_reg->nlink = 0
iput(i_reg) // i_reg->nlink is 0, do evict
ext4_evict_inode
ext4_xattr_delete_inode
ext4_xattr_inode_dec_ref_all
ext4_xattr_inode_iget
ext4_iget(i_ea->i_ino)
iget_locked
find_inode_fast
__wait_on_freeing_inode(i_ea) ----→ AA deadlock
dispose_list // cannot be executed by prune_icache_sb
wake_up_bit(&i_ea->i_state)
Case 2: In deleted inode writing function ubifs_jnl_write_inode(), file
deleting process holds BASEHD's wbuf->io_mutex while getting the
xattr inode, which could race with inode reclaiming process(The
reclaiming process could try locking BASEHD's wbuf->io_mutex in
inode evicting function), then an ABBA deadlock problem would
happen as following:
1. File A has inode ia and a xattr(with inode ixa), regular file B has
inode ib and a xattr.
2. getfattr(A, xattr_buf) // ixa is added into lru // lru->ixa
3. Then, following three processes running like this:
PA PB PC
echo 2 > /proc/sys/vm/drop_caches
shrink_slab
prune_dcache_sb
// ib and ia are added into lru, lru->ixa->ib->ia
prune_icache_sb
list_lru_walk_one
inode_lru_isolate
ixa->i_state |= I_FREEING // set inode state
inode_lru_isolate
__iget(ib)
spin_unlock(&ib->i_lock)
spin_unlock(lru_lock)
rm file B
ib->nlink = 0
rm file A
iput(ia)
ubifs_evict_inode(ia)
ubifs_jnl_delete_inode(ia)
ubifs_jnl_write_inode(ia)
make_reservation(BASEHD) // Lock wbuf->io_mutex
ubifs_iget(ixa->i_ino)
iget_locked
find_inode_fast
__wait_on_freeing_inode(ixa)
| iput(ib) // ib->nlink is 0, do evict
| ubifs_evict_inode
| ubifs_jnl_delete_inode(ib)
↓ ubifs_jnl_write_inode
ABBA deadlock ←-----make_reservation(BASEHD)
dispose_list // cannot be executed by prune_icache_sb
wake_up_bit(&ixa->i_state)
Fix the possible deadlock by using new inode state flag I_LRU_ISOLATING
to pin the inode in memory while inode_lru_isolate(
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
rtla/osnoise: Prevent NULL dereference in error handling
If the "tool->data" allocation fails then there is no need to call
osnoise_free_top() and, in fact, doing so will lead to a NULL dereference. |
| In the Linux kernel, the following vulnerability has been resolved:
fs/netfs/fscache_cookie: add missing "n_accesses" check
This fixes a NULL pointer dereference bug due to a data race which
looks like this:
BUG: kernel NULL pointer dereference, address: 0000000000000008
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
CPU: 33 PID: 16573 Comm: kworker/u97:799 Not tainted 6.8.7-cm4all1-hp+ #43
Hardware name: HP ProLiant DL380 Gen9/ProLiant DL380 Gen9, BIOS P89 10/17/2018
Workqueue: events_unbound netfs_rreq_write_to_cache_work
RIP: 0010:cachefiles_prepare_write+0x30/0xa0
Code: 57 41 56 45 89 ce 41 55 49 89 cd 41 54 49 89 d4 55 53 48 89 fb 48 83 ec 08 48 8b 47 08 48 83 7f 10 00 48 89 34 24 48 8b 68 20 <48> 8b 45 08 4c 8b 38 74 45 49 8b 7f 50 e8 4e a9 b0 ff 48 8b 73 10
RSP: 0018:ffffb4e78113bde0 EFLAGS: 00010286
RAX: ffff976126be6d10 RBX: ffff97615cdb8438 RCX: 0000000000020000
RDX: ffff97605e6c4c68 RSI: ffff97605e6c4c60 RDI: ffff97615cdb8438
RBP: 0000000000000000 R08: 0000000000278333 R09: 0000000000000001
R10: ffff97605e6c4600 R11: 0000000000000001 R12: ffff97605e6c4c68
R13: 0000000000020000 R14: 0000000000000001 R15: ffff976064fe2c00
FS: 0000000000000000(0000) GS:ffff9776dfd40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 000000005942c002 CR4: 00000000001706f0
Call Trace:
<TASK>
? __die+0x1f/0x70
? page_fault_oops+0x15d/0x440
? search_module_extables+0xe/0x40
? fixup_exception+0x22/0x2f0
? exc_page_fault+0x5f/0x100
? asm_exc_page_fault+0x22/0x30
? cachefiles_prepare_write+0x30/0xa0
netfs_rreq_write_to_cache_work+0x135/0x2e0
process_one_work+0x137/0x2c0
worker_thread+0x2e9/0x400
? __pfx_worker_thread+0x10/0x10
kthread+0xcc/0x100
? __pfx_kthread+0x10/0x10
ret_from_fork+0x30/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1b/0x30
</TASK>
Modules linked in:
CR2: 0000000000000008
---[ end trace 0000000000000000 ]---
This happened because fscache_cookie_state_machine() was slow and was
still running while another process invoked fscache_unuse_cookie();
this led to a fscache_cookie_lru_do_one() call, setting the
FSCACHE_COOKIE_DO_LRU_DISCARD flag, which was picked up by
fscache_cookie_state_machine(), withdrawing the cookie via
cachefiles_withdraw_cookie(), clearing cookie->cache_priv.
At the same time, yet another process invoked
cachefiles_prepare_write(), which found a NULL pointer in this code
line:
struct cachefiles_object *object = cachefiles_cres_object(cres);
The next line crashes, obviously:
struct cachefiles_cache *cache = object->volume->cache;
During cachefiles_prepare_write(), the "n_accesses" counter is
non-zero (via fscache_begin_operation()). The cookie must not be
withdrawn until it drops to zero.
The counter is checked by fscache_cookie_state_machine() before
switching to FSCACHE_COOKIE_STATE_RELINQUISHING and
FSCACHE_COOKIE_STATE_WITHDRAWING (in "case
FSCACHE_COOKIE_STATE_FAILED"), but not for
FSCACHE_COOKIE_STATE_LRU_DISCARDING ("case
FSCACHE_COOKIE_STATE_ACTIVE").
This patch adds the missing check. With a non-zero access counter,
the function returns and the next fscache_end_cookie_access() call
will queue another fscache_cookie_state_machine() call to handle the
still-pending FSCACHE_COOKIE_DO_LRU_DISCARD. |
| In the Linux kernel, the following vulnerability has been resolved:
gtp: pull network headers in gtp_dev_xmit()
syzbot/KMSAN reported use of uninit-value in get_dev_xmit() [1]
We must make sure the IPv4 or Ipv6 header is pulled in skb->head
before accessing fields in them.
Use pskb_inet_may_pull() to fix this issue.
[1]
BUG: KMSAN: uninit-value in ipv6_pdp_find drivers/net/gtp.c:220 [inline]
BUG: KMSAN: uninit-value in gtp_build_skb_ip6 drivers/net/gtp.c:1229 [inline]
BUG: KMSAN: uninit-value in gtp_dev_xmit+0x1424/0x2540 drivers/net/gtp.c:1281
ipv6_pdp_find drivers/net/gtp.c:220 [inline]
gtp_build_skb_ip6 drivers/net/gtp.c:1229 [inline]
gtp_dev_xmit+0x1424/0x2540 drivers/net/gtp.c:1281
__netdev_start_xmit include/linux/netdevice.h:4913 [inline]
netdev_start_xmit include/linux/netdevice.h:4922 [inline]
xmit_one net/core/dev.c:3580 [inline]
dev_hard_start_xmit+0x247/0xa20 net/core/dev.c:3596
__dev_queue_xmit+0x358c/0x5610 net/core/dev.c:4423
dev_queue_xmit include/linux/netdevice.h:3105 [inline]
packet_xmit+0x9c/0x6c0 net/packet/af_packet.c:276
packet_snd net/packet/af_packet.c:3145 [inline]
packet_sendmsg+0x90e3/0xa3a0 net/packet/af_packet.c:3177
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0x30f/0x380 net/socket.c:745
__sys_sendto+0x685/0x830 net/socket.c:2204
__do_sys_sendto net/socket.c:2216 [inline]
__se_sys_sendto net/socket.c:2212 [inline]
__x64_sys_sendto+0x125/0x1d0 net/socket.c:2212
x64_sys_call+0x3799/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:45
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Uninit was created at:
slab_post_alloc_hook mm/slub.c:3994 [inline]
slab_alloc_node mm/slub.c:4037 [inline]
kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4080
kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:583
__alloc_skb+0x363/0x7b0 net/core/skbuff.c:674
alloc_skb include/linux/skbuff.h:1320 [inline]
alloc_skb_with_frags+0xc8/0xbf0 net/core/skbuff.c:6526
sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2815
packet_alloc_skb net/packet/af_packet.c:2994 [inline]
packet_snd net/packet/af_packet.c:3088 [inline]
packet_sendmsg+0x749c/0xa3a0 net/packet/af_packet.c:3177
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0x30f/0x380 net/socket.c:745
__sys_sendto+0x685/0x830 net/socket.c:2204
__do_sys_sendto net/socket.c:2216 [inline]
__se_sys_sendto net/socket.c:2212 [inline]
__x64_sys_sendto+0x125/0x1d0 net/socket.c:2212
x64_sys_call+0x3799/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:45
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
CPU: 0 UID: 0 PID: 7115 Comm: syz.1.515 Not tainted 6.11.0-rc1-syzkaller-00043-g94ede2a3e913 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 |
| In the Linux kernel, the following vulnerability has been resolved:
atm: idt77252: prevent use after free in dequeue_rx()
We can't dereference "skb" after calling vcc->push() because the skb
is released. |
| In the Linux kernel, the following vulnerability has been resolved:
net: hns3: fix a deadlock problem when config TC during resetting
When config TC during the reset process, may cause a deadlock, the flow is
as below:
pf reset start
│
▼
......
setup tc │
│ ▼
▼ DOWN: napi_disable()
napi_disable()(skip) │
│ │
▼ ▼
...... ......
│ │
▼ │
napi_enable() │
▼
UINIT: netif_napi_del()
│
▼
......
│
▼
INIT: netif_napi_add()
│
▼
...... global reset start
│ │
▼ ▼
UP: napi_enable()(skip) ......
│ │
▼ ▼
...... napi_disable()
In reset process, the driver will DOWN the port and then UINIT, in this
case, the setup tc process will UP the port before UINIT, so cause the
problem. Adds a DOWN process in UINIT to fix it. |
| In the Linux kernel, the following vulnerability has been resolved:
tcp: prevent concurrent execution of tcp_sk_exit_batch
Its possible that two threads call tcp_sk_exit_batch() concurrently,
once from the cleanup_net workqueue, once from a task that failed to clone
a new netns. In the latter case, error unwinding calls the exit handlers
in reverse order for the 'failed' netns.
tcp_sk_exit_batch() calls tcp_twsk_purge().
Problem is that since commit b099ce2602d8 ("net: Batch inet_twsk_purge"),
this function picks up twsk in any dying netns, not just the one passed
in via exit_batch list.
This means that the error unwind of setup_net() can "steal" and destroy
timewait sockets belonging to the exiting netns.
This allows the netns exit worker to proceed to call
WARN_ON_ONCE(!refcount_dec_and_test(&net->ipv4.tcp_death_row.tw_refcount));
without the expected 1 -> 0 transition, which then splats.
At same time, error unwind path that is also running inet_twsk_purge()
will splat as well:
WARNING: .. at lib/refcount.c:31 refcount_warn_saturate+0x1ed/0x210
...
refcount_dec include/linux/refcount.h:351 [inline]
inet_twsk_kill+0x758/0x9c0 net/ipv4/inet_timewait_sock.c:70
inet_twsk_deschedule_put net/ipv4/inet_timewait_sock.c:221
inet_twsk_purge+0x725/0x890 net/ipv4/inet_timewait_sock.c:304
tcp_sk_exit_batch+0x1c/0x170 net/ipv4/tcp_ipv4.c:3522
ops_exit_list+0x128/0x180 net/core/net_namespace.c:178
setup_net+0x714/0xb40 net/core/net_namespace.c:375
copy_net_ns+0x2f0/0x670 net/core/net_namespace.c:508
create_new_namespaces+0x3ea/0xb10 kernel/nsproxy.c:110
... because refcount_dec() of tw_refcount unexpectedly dropped to 0.
This doesn't seem like an actual bug (no tw sockets got lost and I don't
see a use-after-free) but as erroneous trigger of debug check.
Add a mutex to force strict ordering: the task that calls tcp_twsk_purge()
blocks other task from doing final _dec_and_test before mutex-owner has
removed all tw sockets of dying netns. |
| In the Linux kernel, the following vulnerability has been resolved:
bonding: fix null pointer deref in bond_ipsec_offload_ok
We must check if there is an active slave before dereferencing the pointer. |
