| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| nscd: Stack-based buffer overflow in netgroup cache
If the Name Service Cache Daemon's (nscd) fixed size cache is exhausted
by client requests then a subsequent client request for netgroup data
may result in a stack-based buffer overflow. This flaw was introduced
in glibc 2.15 when the cache was added to nscd.
This vulnerability is only present in the nscd binary. |
| The iconv() function in the GNU C Library versions 2.39 and older may overflow the output buffer passed to it by up to 4 bytes when converting strings to the ISO-2022-CN-EXT character set, which may be used to crash an application or overwrite a neighbouring variable. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: use timestamp to check for set element timeout
Add a timestamp field at the beginning of the transaction, store it
in the nftables per-netns area.
Update set backend .insert, .deactivate and sync gc path to use the
timestamp, this avoids that an element expires while control plane
transaction is still unfinished.
.lookup and .update, which are used from packet path, still use the
current time to check if the element has expired. And .get path and dump
also since this runs lockless under rcu read size lock. Then, there is
async gc which also needs to check the current time since it runs
asynchronously from a workqueue. |
| In the Linux kernel, the following vulnerability has been resolved:
net: gtp: Fix Use-After-Free in gtp_dellink
Since call_rcu, which is called in the hlist_for_each_entry_rcu traversal
of gtp_dellink, is not part of the RCU read critical section, it
is possible that the RCU grace period will pass during the traversal and
the key will be free.
To prevent this, it should be changed to hlist_for_each_entry_safe. |
| In the Linux kernel, the following vulnerability has been resolved:
net: openvswitch: Fix Use-After-Free in ovs_ct_exit
Since kfree_rcu, which is called in the hlist_for_each_entry_rcu traversal
of ovs_ct_limit_exit, is not part of the RCU read critical section, it
is possible that the RCU grace period will pass during the traversal and
the key will be free.
To prevent this, it should be changed to hlist_for_each_entry_safe. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: do not compare internal table flags on updates
Restore skipping transaction if table update does not modify flags. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: rtl8xxxu: add cancel_work_sync() for c2hcmd_work
The workqueue might still be running, when the driver is stopped. To
avoid a use-after-free, call cancel_work_sync() in rtl8xxxu_stop(). |
| In the Linux kernel, the following vulnerability has been resolved:
net/rds: fix WARNING in rds_conn_connect_if_down
If connection isn't established yet, get_mr() will fail, trigger connection after
get_mr(). |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: Fix potential data-race in __nft_expr_type_get()
nft_unregister_expr() can concurrent with __nft_expr_type_get(),
and there is not any protection when iterate over nf_tables_expressions
list in __nft_expr_type_get(). Therefore, there is potential data-race
of nf_tables_expressions list entry.
Use list_for_each_entry_rcu() to iterate over nf_tables_expressions
list in __nft_expr_type_get(), and use rcu_read_lock() in the caller
nft_expr_type_get() to protect the entire type query process. |
| In the Linux kernel, the following vulnerability has been resolved:
init/main.c: Fix potential static_command_line memory overflow
We allocate memory of size 'xlen + strlen(boot_command_line) + 1' for
static_command_line, but the strings copied into static_command_line are
extra_command_line and command_line, rather than extra_command_line and
boot_command_line.
When strlen(command_line) > strlen(boot_command_line), static_command_line
will overflow.
This patch just recovers strlen(command_line) which was miss-consolidated
with strlen(boot_command_line) in the commit f5c7310ac73e ("init/main: add
checks for the return value of memblock_alloc*()") |
| In the Linux kernel, the following vulnerability has been resolved:
Squashfs: check the inode number is not the invalid value of zero
Syskiller has produced an out of bounds access in fill_meta_index().
That out of bounds access is ultimately caused because the inode
has an inode number with the invalid value of zero, which was not checked.
The reason this causes the out of bounds access is due to following
sequence of events:
1. Fill_meta_index() is called to allocate (via empty_meta_index())
and fill a metadata index. It however suffers a data read error
and aborts, invalidating the newly returned empty metadata index.
It does this by setting the inode number of the index to zero,
which means unused (zero is not a valid inode number).
2. When fill_meta_index() is subsequently called again on another
read operation, locate_meta_index() returns the previous index
because it matches the inode number of 0. Because this index
has been returned it is expected to have been filled, and because
it hasn't been, an out of bounds access is performed.
This patch adds a sanity check which checks that the inode number
is not zero when the inode is created and returns -EINVAL if it is.
[phillip@squashfs.org.uk: whitespace fix] |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: qat - resolve race condition during AER recovery
During the PCI AER system's error recovery process, the kernel driver
may encounter a race condition with freeing the reset_data structure's
memory. If the device restart will take more than 10 seconds the function
scheduling that restart will exit due to a timeout, and the reset_data
structure will be freed. However, this data structure is used for
completion notification after the restart is completed, which leads
to a UAF bug.
This results in a KFENCE bug notice.
BUG: KFENCE: use-after-free read in adf_device_reset_worker+0x38/0xa0 [intel_qat]
Use-after-free read at 0x00000000bc56fddf (in kfence-#142):
adf_device_reset_worker+0x38/0xa0 [intel_qat]
process_one_work+0x173/0x340
To resolve this race condition, the memory associated to the container
of the work_struct is freed on the worker if the timeout expired,
otherwise on the function that schedules the worker.
The timeout detection can be done by checking if the caller is
still waiting for completion or not by using completion_done() function. |
| In the Linux kernel, the following vulnerability has been resolved:
mac802154: fix llsec key resources release in mac802154_llsec_key_del
mac802154_llsec_key_del() can free resources of a key directly without
following the RCU rules for waiting before the end of a grace period. This
may lead to use-after-free in case llsec_lookup_key() is traversing the
list of keys in parallel with a key deletion:
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 4 PID: 16000 at lib/refcount.c:25 refcount_warn_saturate+0x162/0x2a0
Modules linked in:
CPU: 4 PID: 16000 Comm: wpan-ping Not tainted 6.7.0 #19
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:refcount_warn_saturate+0x162/0x2a0
Call Trace:
<TASK>
llsec_lookup_key.isra.0+0x890/0x9e0
mac802154_llsec_encrypt+0x30c/0x9c0
ieee802154_subif_start_xmit+0x24/0x1e0
dev_hard_start_xmit+0x13e/0x690
sch_direct_xmit+0x2ae/0xbc0
__dev_queue_xmit+0x11dd/0x3c20
dgram_sendmsg+0x90b/0xd60
__sys_sendto+0x466/0x4c0
__x64_sys_sendto+0xe0/0x1c0
do_syscall_64+0x45/0xf0
entry_SYSCALL_64_after_hwframe+0x6e/0x76
Also, ieee802154_llsec_key_entry structures are not freed by
mac802154_llsec_key_del():
unreferenced object 0xffff8880613b6980 (size 64):
comm "iwpan", pid 2176, jiffies 4294761134 (age 60.475s)
hex dump (first 32 bytes):
78 0d 8f 18 80 88 ff ff 22 01 00 00 00 00 ad de x.......".......
00 00 00 00 00 00 00 00 03 00 cd ab 00 00 00 00 ................
backtrace:
[<ffffffff81dcfa62>] __kmem_cache_alloc_node+0x1e2/0x2d0
[<ffffffff81c43865>] kmalloc_trace+0x25/0xc0
[<ffffffff88968b09>] mac802154_llsec_key_add+0xac9/0xcf0
[<ffffffff8896e41a>] ieee802154_add_llsec_key+0x5a/0x80
[<ffffffff8892adc6>] nl802154_add_llsec_key+0x426/0x5b0
[<ffffffff86ff293e>] genl_family_rcv_msg_doit+0x1fe/0x2f0
[<ffffffff86ff46d1>] genl_rcv_msg+0x531/0x7d0
[<ffffffff86fee7a9>] netlink_rcv_skb+0x169/0x440
[<ffffffff86ff1d88>] genl_rcv+0x28/0x40
[<ffffffff86fec15c>] netlink_unicast+0x53c/0x820
[<ffffffff86fecd8b>] netlink_sendmsg+0x93b/0xe60
[<ffffffff86b91b35>] ____sys_sendmsg+0xac5/0xca0
[<ffffffff86b9c3dd>] ___sys_sendmsg+0x11d/0x1c0
[<ffffffff86b9c65a>] __sys_sendmsg+0xfa/0x1d0
[<ffffffff88eadbf5>] do_syscall_64+0x45/0xf0
[<ffffffff890000ea>] entry_SYSCALL_64_after_hwframe+0x6e/0x76
Handle the proper resource release in the RCU callback function
mac802154_llsec_key_del_rcu().
Note that if llsec_lookup_key() finds a key, it gets a refcount via
llsec_key_get() and locally copies key id from key_entry (which is a
list element). So it's safe to call llsec_key_put() and free the list
entry after the RCU grace period elapses.
Found by Linux Verification Center (linuxtesting.org). |
| In the Linux kernel, the following vulnerability has been resolved:
nfs: fix UAF in direct writes
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. |
| In the Linux kernel, the following vulnerability has been resolved:
wireguard: netlink: check for dangling peer via is_dead instead of empty list
If all peers are removed via wg_peer_remove_all(), rather than setting
peer_list to empty, the peer is added to a temporary list with a head on
the stack of wg_peer_remove_all(). If a netlink dump is resumed and the
cursored peer is one that has been removed via wg_peer_remove_all(), it
will iterate from that peer and then attempt to dump freed peers.
Fix this by instead checking peer->is_dead, which was explictly created
for this purpose. Also move up the device_update_lock lockdep assertion,
since reading is_dead relies on that.
It can be reproduced by a small script like:
echo "Setting config..."
ip link add dev wg0 type wireguard
wg setconf wg0 /big-config
(
while true; do
echo "Showing config..."
wg showconf wg0 > /dev/null
done
) &
sleep 4
wg setconf wg0 <(printf "[Peer]\nPublicKey=$(wg genkey)\n")
Resulting in:
BUG: KASAN: slab-use-after-free in __lock_acquire+0x182a/0x1b20
Read of size 8 at addr ffff88811956ec70 by task wg/59
CPU: 2 PID: 59 Comm: wg Not tainted 6.8.0-rc2-debug+ #5
Call Trace:
<TASK>
dump_stack_lvl+0x47/0x70
print_address_description.constprop.0+0x2c/0x380
print_report+0xab/0x250
kasan_report+0xba/0xf0
__lock_acquire+0x182a/0x1b20
lock_acquire+0x191/0x4b0
down_read+0x80/0x440
get_peer+0x140/0xcb0
wg_get_device_dump+0x471/0x1130 |
| In the Linux kernel, the following vulnerability has been resolved:
USB: core: Fix deadlock in usb_deauthorize_interface()
Among the attribute file callback routines in
drivers/usb/core/sysfs.c, the interface_authorized_store() function is
the only one which acquires a device lock on an ancestor device: It
calls usb_deauthorize_interface(), which locks the interface's parent
USB device.
The will lead to deadlock if another process already owns that lock
and tries to remove the interface, whether through a configuration
change or because the device has been disconnected. As part of the
removal procedure, device_del() waits for all ongoing sysfs attribute
callbacks to complete. But usb_deauthorize_interface() can't complete
until the device lock has been released, and the lock won't be
released until the removal has finished.
The mechanism provided by sysfs to prevent this kind of deadlock is
to use the sysfs_break_active_protection() function, which tells sysfs
not to wait for the attribute callback.
Reported-and-tested by: Yue Sun <samsun1006219@gmail.com>
Reported by: xingwei lee <xrivendell7@gmail.com> |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/mlx5: Fix fortify source warning while accessing Eth segment
------------[ cut here ]------------
memcpy: detected field-spanning write (size 56) of single field "eseg->inline_hdr.start" at /var/lib/dkms/mlnx-ofed-kernel/5.8/build/drivers/infiniband/hw/mlx5/wr.c:131 (size 2)
WARNING: CPU: 0 PID: 293779 at /var/lib/dkms/mlnx-ofed-kernel/5.8/build/drivers/infiniband/hw/mlx5/wr.c:131 mlx5_ib_post_send+0x191b/0x1a60 [mlx5_ib]
Modules linked in: 8021q garp mrp stp llc rdma_ucm(OE) rdma_cm(OE) iw_cm(OE) ib_ipoib(OE) ib_cm(OE) ib_umad(OE) mlx5_ib(OE) ib_uverbs(OE) ib_core(OE) mlx5_core(OE) pci_hyperv_intf mlxdevm(OE) mlx_compat(OE) tls mlxfw(OE) psample nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables libcrc32c nfnetlink mst_pciconf(OE) knem(OE) vfio_pci vfio_pci_core vfio_iommu_type1 vfio iommufd irqbypass cuse nfsv3 nfs fscache netfs xfrm_user xfrm_algo ipmi_devintf ipmi_msghandler binfmt_misc crct10dif_pclmul crc32_pclmul polyval_clmulni polyval_generic ghash_clmulni_intel sha512_ssse3 snd_pcsp aesni_intel crypto_simd cryptd snd_pcm snd_timer joydev snd soundcore input_leds serio_raw evbug nfsd auth_rpcgss nfs_acl lockd grace sch_fq_codel sunrpc drm efi_pstore ip_tables x_tables autofs4 psmouse virtio_net net_failover failover floppy
[last unloaded: mlx_compat(OE)]
CPU: 0 PID: 293779 Comm: ssh Tainted: G OE 6.2.0-32-generic #32~22.04.1-Ubuntu
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
RIP: 0010:mlx5_ib_post_send+0x191b/0x1a60 [mlx5_ib]
Code: 0c 01 00 a8 01 75 25 48 8b 75 a0 b9 02 00 00 00 48 c7 c2 10 5b fd c0 48 c7 c7 80 5b fd c0 c6 05 57 0c 03 00 01 e8 95 4d 93 da <0f> 0b 44 8b 4d b0 4c 8b 45 c8 48 8b 4d c0 e9 49 fb ff ff 41 0f b7
RSP: 0018:ffffb5b48478b570 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffb5b48478b628 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffb5b48478b5e8
R13: ffff963a3c609b5e R14: ffff9639c3fbd800 R15: ffffb5b480475a80
FS: 00007fc03b444c80(0000) GS:ffff963a3dc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556f46bdf000 CR3: 0000000006ac6003 CR4: 00000000003706f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
? show_regs+0x72/0x90
? mlx5_ib_post_send+0x191b/0x1a60 [mlx5_ib]
? __warn+0x8d/0x160
? mlx5_ib_post_send+0x191b/0x1a60 [mlx5_ib]
? report_bug+0x1bb/0x1d0
? handle_bug+0x46/0x90
? exc_invalid_op+0x19/0x80
? asm_exc_invalid_op+0x1b/0x20
? mlx5_ib_post_send+0x191b/0x1a60 [mlx5_ib]
mlx5_ib_post_send_nodrain+0xb/0x20 [mlx5_ib]
ipoib_send+0x2ec/0x770 [ib_ipoib]
ipoib_start_xmit+0x5a0/0x770 [ib_ipoib]
dev_hard_start_xmit+0x8e/0x1e0
? validate_xmit_skb_list+0x4d/0x80
sch_direct_xmit+0x116/0x3a0
__dev_xmit_skb+0x1fd/0x580
__dev_queue_xmit+0x284/0x6b0
? _raw_spin_unlock_irq+0xe/0x50
? __flush_work.isra.0+0x20d/0x370
? push_pseudo_header+0x17/0x40 [ib_ipoib]
neigh_connected_output+0xcd/0x110
ip_finish_output2+0x179/0x480
? __smp_call_single_queue+0x61/0xa0
__ip_finish_output+0xc3/0x190
ip_finish_output+0x2e/0xf0
ip_output+0x78/0x110
? __pfx_ip_finish_output+0x10/0x10
ip_local_out+0x64/0x70
__ip_queue_xmit+0x18a/0x460
ip_queue_xmit+0x15/0x30
__tcp_transmit_skb+0x914/0x9c0
tcp_write_xmit+0x334/0x8d0
tcp_push_one+0x3c/0x60
tcp_sendmsg_locked+0x2e1/0xac0
tcp_sendmsg+0x2d/0x50
inet_sendmsg+0x43/0x90
sock_sendmsg+0x68/0x80
sock_write_iter+0x93/0x100
vfs_write+0x326/0x3c0
ksys_write+0xbd/0xf0
? do_syscall_64+0x69/0x90
__x64_sys_write+0x19/0x30
do_syscall_
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
aoe: fix the potential use-after-free problem in aoecmd_cfg_pkts
This patch is against CVE-2023-6270. The description of cve is:
A flaw was found in the ATA over Ethernet (AoE) driver in the Linux
kernel. The aoecmd_cfg_pkts() function improperly updates the refcnt on
`struct net_device`, and a use-after-free can be triggered by racing
between the free on the struct and the access through the `skbtxq`
global queue. This could lead to a denial of service condition or
potential code execution.
In aoecmd_cfg_pkts(), it always calls dev_put(ifp) when skb initial
code is finished. But the net_device ifp will still be used in
later tx()->dev_queue_xmit() in kthread. Which means that the
dev_put(ifp) should NOT be called in the success path of skb
initial code in aoecmd_cfg_pkts(). Otherwise tx() may run into
use-after-free because the net_device is freed.
This patch removed the dev_put(ifp) in the success path in
aoecmd_cfg_pkts(), and added dev_put() after skb xmit in tx(). |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: wilc1000: prevent use-after-free on vif when cleaning up all interfaces
wilc_netdev_cleanup currently triggers a KASAN warning, which can be
observed on interface registration error path, or simply by
removing the module/unbinding device from driver:
echo spi0.1 > /sys/bus/spi/drivers/wilc1000_spi/unbind
==================================================================
BUG: KASAN: slab-use-after-free in wilc_netdev_cleanup+0x508/0x5cc
Read of size 4 at addr c54d1ce8 by task sh/86
CPU: 0 PID: 86 Comm: sh Not tainted 6.8.0-rc1+ #117
Hardware name: Atmel SAMA5
unwind_backtrace from show_stack+0x18/0x1c
show_stack from dump_stack_lvl+0x34/0x58
dump_stack_lvl from print_report+0x154/0x500
print_report from kasan_report+0xac/0xd8
kasan_report from wilc_netdev_cleanup+0x508/0x5cc
wilc_netdev_cleanup from wilc_bus_remove+0xc8/0xec
wilc_bus_remove from spi_remove+0x8c/0xac
spi_remove from device_release_driver_internal+0x434/0x5f8
device_release_driver_internal from unbind_store+0xbc/0x108
unbind_store from kernfs_fop_write_iter+0x398/0x584
kernfs_fop_write_iter from vfs_write+0x728/0xf88
vfs_write from ksys_write+0x110/0x1e4
ksys_write from ret_fast_syscall+0x0/0x1c
[...]
Allocated by task 1:
kasan_save_track+0x30/0x5c
__kasan_kmalloc+0x8c/0x94
__kmalloc_node+0x1cc/0x3e4
kvmalloc_node+0x48/0x180
alloc_netdev_mqs+0x68/0x11dc
alloc_etherdev_mqs+0x28/0x34
wilc_netdev_ifc_init+0x34/0x8ec
wilc_cfg80211_init+0x690/0x910
wilc_bus_probe+0xe0/0x4a0
spi_probe+0x158/0x1b0
really_probe+0x270/0xdf4
__driver_probe_device+0x1dc/0x580
driver_probe_device+0x60/0x140
__driver_attach+0x228/0x5d4
bus_for_each_dev+0x13c/0x1a8
bus_add_driver+0x2a0/0x608
driver_register+0x24c/0x578
do_one_initcall+0x180/0x310
kernel_init_freeable+0x424/0x484
kernel_init+0x20/0x148
ret_from_fork+0x14/0x28
Freed by task 86:
kasan_save_track+0x30/0x5c
kasan_save_free_info+0x38/0x58
__kasan_slab_free+0xe4/0x140
kfree+0xb0/0x238
device_release+0xc0/0x2a8
kobject_put+0x1d4/0x46c
netdev_run_todo+0x8fc/0x11d0
wilc_netdev_cleanup+0x1e4/0x5cc
wilc_bus_remove+0xc8/0xec
spi_remove+0x8c/0xac
device_release_driver_internal+0x434/0x5f8
unbind_store+0xbc/0x108
kernfs_fop_write_iter+0x398/0x584
vfs_write+0x728/0xf88
ksys_write+0x110/0x1e4
ret_fast_syscall+0x0/0x1c
[...]
David Mosberger-Tan initial investigation [1] showed that this
use-after-free is due to netdevice unregistration during vif list
traversal. When unregistering a net device, since the needs_free_netdev has
been set to true during registration, the netdevice object is also freed,
and as a consequence, the corresponding vif object too, since it is
attached to it as private netdevice data. The next occurrence of the loop
then tries to access freed vif pointer to the list to move forward in the
list.
Fix this use-after-free thanks to two mechanisms:
- navigate in the list with list_for_each_entry_safe, which allows to
safely modify the list as we go through each element. For each element,
remove it from the list with list_del_rcu
- make sure to wait for RCU grace period end after each vif removal to make
sure it is safe to free the corresponding vif too (through
unregister_netdev)
Since we are in a RCU "modifier" path (not a "reader" path), and because
such path is expected not to be concurrent to any other modifier (we are
using the vif_mutex lock), we do not need to use RCU list API, that's why
we can benefit from list_for_each_entry_safe.
[1] https://lore.kernel.org/linux-wireless/ab077dbe58b1ea5de0a3b2ca21f275a07af967d2.camel@egauge.net/ |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix DEVMAP_HASH overflow check on 32-bit arches
The devmap code allocates a number hash buckets equal to the next power
of two of the max_entries value provided when creating the map. When
rounding up to the next power of two, the 32-bit variable storing the
number of buckets can overflow, and the code checks for overflow by
checking if the truncated 32-bit value is equal to 0. However, on 32-bit
arches the rounding up itself can overflow mid-way through, because it
ends up doing a left-shift of 32 bits on an unsigned long value. If the
size of an unsigned long is four bytes, this is undefined behaviour, so
there is no guarantee that we'll end up with a nice and tidy 0-value at
the end.
Syzbot managed to turn this into a crash on arm32 by creating a
DEVMAP_HASH with max_entries > 0x80000000 and then trying to update it.
Fix this by moving the overflow check to before the rounding up
operation. |
