In the Linux kernel, the following vulnerability has been resolved:
wifi: nl80211: fix NL80211_ATTR_MLO_LINK_ID off-by-one
Since the netlink attribute range validation provides inclusive
checking, the *max* of attribut...Show moreIn the Linux kernel, the following vulnerability has been resolved:
wifi: nl80211: fix NL80211_ATTR_MLO_LINK_ID off-by-one
Since the netlink attribute range validation provides inclusive
checking, the *max* of attribute NL80211_ATTR_MLO_LINK_ID should be
IEEE80211_MLD_MAX_NUM_LINKS - 1 otherwise causing an off-by-one.
One crash stack for demonstration:
==================================================================
BUG: KASAN: wild-memory-access in ieee80211_tx_control_port+0x3b6/0xca0 net/mac80211/tx.c:5939
Read of size 6 at addr 001102080000000c by task fuzzer.386/9508
CPU: 1 PID: 9508 Comm: syz.1.386 Not tainted 6.1.70 #2
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x177/0x231 lib/dump_stack.c:106
print_report+0xe0/0x750 mm/kasan/report.c:398
kasan_report+0x139/0x170 mm/kasan/report.c:495
kasan_check_range+0x287/0x290 mm/kasan/generic.c:189
memcpy+0x25/0x60 mm/kasan/shadow.c:65
ieee80211_tx_control_port+0x3b6/0xca0 net/mac80211/tx.c:5939
rdev_tx_control_port net/wireless/rdev-ops.h:761 [inline]
nl80211_tx_control_port+0x7b3/0xc40 net/wireless/nl80211.c:15453
genl_family_rcv_msg_doit+0x22e/0x320 net/netlink/genetlink.c:756
genl_family_rcv_msg net/netlink/genetlink.c:833 [inline]
genl_rcv_msg+0x539/0x740 net/netlink/genetlink.c:850
netlink_rcv_skb+0x1de/0x420 net/netlink/af_netlink.c:2508
genl_rcv+0x24/0x40 net/netlink/genetlink.c:861
netlink_unicast_kernel net/netlink/af_netlink.c:1326 [inline]
netlink_unicast+0x74b/0x8c0 net/netlink/af_netlink.c:1352
netlink_sendmsg+0x882/0xb90 net/netlink/af_netlink.c:1874
sock_sendmsg_nosec net/socket.c:716 [inline]
__sock_sendmsg net/socket.c:728 [inline]
____sys_sendmsg+0x5cc/0x8f0 net/socket.c:2499
___sys_sendmsg+0x21c/0x290 net/socket.c:2553
__sys_sendmsg net/socket.c:2582 [inline]
__do_sys_sendmsg net/socket.c:2591 [inline]
__se_sys_sendmsg+0x19e/0x270 net/socket.c:2589
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x45/0x90 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Update the policy to ensure correct validation.Show less |
In the Linux kernel, the following vulnerability has been resolved:
acpi: nfit: vmalloc-out-of-bounds Read in acpi_nfit_ctl
Fix an issue detected by syzbot with KASAN:
BUG: KASAN: vmalloc-out-of-bounds in cmd_to_func...Show moreIn the Linux kernel, the following vulnerability has been resolved:
acpi: nfit: vmalloc-out-of-bounds Read in acpi_nfit_ctl
Fix an issue detected by syzbot with KASAN:
BUG: KASAN: vmalloc-out-of-bounds in cmd_to_func drivers/acpi/nfit/
core.c:416 [inline]
BUG: KASAN: vmalloc-out-of-bounds in acpi_nfit_ctl+0x20e8/0x24a0
drivers/acpi/nfit/core.c:459
The issue occurs in cmd_to_func when the call_pkg->nd_reserved2
array is accessed without verifying that call_pkg points to a buffer
that is appropriately sized as a struct nd_cmd_pkg. This can lead
to out-of-bounds access and undefined behavior if the buffer does not
have sufficient space.
To address this, a check was added in acpi_nfit_ctl() to ensure that
buf is not NULL and that buf_len is less than sizeof(*call_pkg)
before accessing it. This ensures safe access to the members of
call_pkg, including the nd_reserved2 array.Show less |
In the Linux kernel, the following vulnerability has been resolved:
tipc: fix NULL deref in cleanup_bearer()
syzbot found [1] that after blamed commit, ub->ubsock->sk
was NULL when attempting the atomic_dec() :
atomic...Show moreIn the Linux kernel, the following vulnerability has been resolved:
tipc: fix NULL deref in cleanup_bearer()
syzbot found [1] that after blamed commit, ub->ubsock->sk
was NULL when attempting the atomic_dec() :
atomic_dec(&tipc_net(sock_net(ub->ubsock->sk))->wq_count);
Fix this by caching the tipc_net pointer.
[1]
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]
CPU: 0 UID: 0 PID: 5896 Comm: kworker/0:3 Not tainted 6.13.0-rc1-next-20241203-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events cleanup_bearer
RIP: 0010:read_pnet include/net/net_namespace.h:387 [inline]
RIP: 0010:sock_net include/net/sock.h:655 [inline]
RIP: 0010:cleanup_bearer+0x1f7/0x280 net/tipc/udp_media.c:820
Code: 18 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 3c f7 99 f6 48 8b 1b 48 83 c3 30 e8 f0 e4 60 00 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 74 08 48 89 df e8 1a f7 99 f6 49 83 c7 e8 48 8b 1b
RSP: 0018:ffffc9000410fb70 EFLAGS: 00010206
RAX: 0000000000000006 RBX: 0000000000000030 RCX: ffff88802fe45a00
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffc9000410f900
RBP: ffff88807e1f0908 R08: ffffc9000410f907 R09: 1ffff92000821f20
R10: dffffc0000000000 R11: fffff52000821f21 R12: ffff888031d19980
R13: dffffc0000000000 R14: dffffc0000000000 R15: ffff88807e1f0918
FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556ca050b000 CR3: 0000000031c0c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400Show less |
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: DR, prevent potential error pointer dereference
The dr_domain_add_vport_cap() function generally returns NULL on error
but sometimes we want...Show moreIn the Linux kernel, the following vulnerability has been resolved:
net/mlx5: DR, prevent potential error pointer dereference
The dr_domain_add_vport_cap() function generally returns NULL on error
but sometimes we want it to return ERR_PTR(-EBUSY) so the caller can
retry. The problem here is that "ret" can be either -EBUSY or -ENOMEM
and if it's and -ENOMEM then the error pointer is propogated back and
eventually dereferenced in dr_ste_v0_build_src_gvmi_qpn_tag().Show less |
In the Linux kernel, the following vulnerability has been resolved:
net: lapb: increase LAPB_HEADER_LEN
It is unclear if net/lapb code is supposed to be ready for 8021q.
We can at least avoid crashes like the followin...Show moreIn the Linux kernel, the following vulnerability has been resolved:
net: lapb: increase LAPB_HEADER_LEN
It is unclear if net/lapb code is supposed to be ready for 8021q.
We can at least avoid crashes like the following :
skbuff: skb_under_panic: text:ffffffff8aabe1f6 len:24 put:20 head:ffff88802824a400 data:ffff88802824a3fe tail:0x16 end:0x140 dev:nr0.2
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:206 !
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 5508 Comm: dhcpcd Not tainted 6.12.0-rc7-syzkaller-00144-g66418447d27b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
RIP: 0010:skb_panic net/core/skbuff.c:206 [inline]
RIP: 0010:skb_under_panic+0x14b/0x150 net/core/skbuff.c:216
Code: 0d 8d 48 c7 c6 2e 9e 29 8e 48 8b 54 24 08 8b 0c 24 44 8b 44 24 04 4d 89 e9 50 41 54 41 57 41 56 e8 1a 6f 37 02 48 83 c4 20 90 <0f> 0b 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3
RSP: 0018:ffffc90002ddf638 EFLAGS: 00010282
RAX: 0000000000000086 RBX: dffffc0000000000 RCX: 7a24750e538ff600
RDX: 0000000000000000 RSI: 0000000000000201 RDI: 0000000000000000
RBP: ffff888034a86650 R08: ffffffff8174b13c R09: 1ffff920005bbe60
R10: dffffc0000000000 R11: fffff520005bbe61 R12: 0000000000000140
R13: ffff88802824a400 R14: ffff88802824a3fe R15: 0000000000000016
FS: 00007f2a5990d740(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2631fd CR3: 0000000029504000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
skb_push+0xe5/0x100 net/core/skbuff.c:2636
nr_header+0x36/0x320 net/netrom/nr_dev.c:69
dev_hard_header include/linux/netdevice.h:3148 [inline]
vlan_dev_hard_header+0x359/0x480 net/8021q/vlan_dev.c:83
dev_hard_header include/linux/netdevice.h:3148 [inline]
lapbeth_data_transmit+0x1f6/0x2a0 drivers/net/wan/lapbether.c:257
lapb_data_transmit+0x91/0xb0 net/lapb/lapb_iface.c:447
lapb_transmit_buffer+0x168/0x1f0 net/lapb/lapb_out.c:149
lapb_establish_data_link+0x84/0xd0
lapb_device_event+0x4e0/0x670
notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
__dev_notify_flags+0x207/0x400
dev_change_flags+0xf0/0x1a0 net/core/dev.c:8922
devinet_ioctl+0xa4e/0x1aa0 net/ipv4/devinet.c:1188
inet_ioctl+0x3d7/0x4f0 net/ipv4/af_inet.c:1003
sock_do_ioctl+0x158/0x460 net/socket.c:1227
sock_ioctl+0x626/0x8e0 net/socket.c:1346
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83Show less |
In the Linux kernel, the following vulnerability has been resolved:
net: defer final 'struct net' free in netns dismantle
Ilya reported a slab-use-after-free in dst_destroy [1]
Issue is in xfrm6_net_init() and xfrm4_n...Show moreIn the Linux kernel, the following vulnerability has been resolved:
net: defer final 'struct net' free in netns dismantle
Ilya reported a slab-use-after-free in dst_destroy [1]
Issue is in xfrm6_net_init() and xfrm4_net_init() :
They copy xfrm[46]_dst_ops_template into net->xfrm.xfrm[46]_dst_ops.
But net structure might be freed before all the dst callbacks are
called. So when dst_destroy() calls later :
if (dst->ops->destroy)
dst->ops->destroy(dst);
dst->ops points to the old net->xfrm.xfrm[46]_dst_ops, which has been freed.
See a relevant issue fixed in :
ac888d58869b ("net: do not delay dst_entries_add() in dst_release()")
A fix is to queue the 'struct net' to be freed after one
another cleanup_net() round (and existing rcu_barrier())
[1]
BUG: KASAN: slab-use-after-free in dst_destroy (net/core/dst.c:112)
Read of size 8 at addr ffff8882137ccab0 by task swapper/37/0
Dec 03 05:46:18 kernel:
CPU: 37 UID: 0 PID: 0 Comm: swapper/37 Kdump: loaded Not tainted 6.12.0 #67
Hardware name: Red Hat KVM/RHEL, BIOS 1.16.1-1.el9 04/01/2014
Call Trace:
<IRQ>
dump_stack_lvl (lib/dump_stack.c:124)
print_address_description.constprop.0 (mm/kasan/report.c:378)
? dst_destroy (net/core/dst.c:112)
print_report (mm/kasan/report.c:489)
? dst_destroy (net/core/dst.c:112)
? kasan_addr_to_slab (mm/kasan/common.c:37)
kasan_report (mm/kasan/report.c:603)
? dst_destroy (net/core/dst.c:112)
? rcu_do_batch (kernel/rcu/tree.c:2567)
dst_destroy (net/core/dst.c:112)
rcu_do_batch (kernel/rcu/tree.c:2567)
? __pfx_rcu_do_batch (kernel/rcu/tree.c:2491)
? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4339 kernel/locking/lockdep.c:4406)
rcu_core (kernel/rcu/tree.c:2825)
handle_softirqs (kernel/softirq.c:554)
__irq_exit_rcu (kernel/softirq.c:589 kernel/softirq.c:428 kernel/softirq.c:637)
irq_exit_rcu (kernel/softirq.c:651)
sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1049 arch/x86/kernel/apic/apic.c:1049)
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702)
RIP: 0010:default_idle (./arch/x86/include/asm/irqflags.h:37 ./arch/x86/include/asm/irqflags.h:92 arch/x86/kernel/process.c:743)
Code: 00 4d 29 c8 4c 01 c7 4c 29 c2 e9 6e ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 90 0f 00 2d c7 c9 27 00 fb f4 <fa> c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90
RSP: 0018:ffff888100d2fe00 EFLAGS: 00000246
RAX: 00000000001870ed RBX: 1ffff110201a5fc2 RCX: ffffffffb61a3e46
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffb3d4d123
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed11c7e1835d
R10: ffff888e3f0c1aeb R11: 0000000000000000 R12: 0000000000000000
R13: ffff888100d20000 R14: dffffc0000000000 R15: 0000000000000000
? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:148)
? cpuidle_idle_call (kernel/sched/idle.c:186)
default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118)
cpuidle_idle_call (kernel/sched/idle.c:186)
? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168)
? lock_release (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5848)
? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59)
do_idle (kernel/sched/idle.c:326)
cpu_startup_entry (kernel/sched/idle.c:423 (discriminator 1))
start_secondary (arch/x86/kernel/smpboot.c:202 arch/x86/kernel/smpboot.c:282)
? __pfx_start_secondary (arch/x86/kernel/smpboot.c:232)
? soft_restart_cpu (arch/x86/kernel/head_64.S:452)
common_startup_64 (arch/x86/kernel/head_64.S:414)
</TASK>
Dec 03 05:46:18 kernel:
Allocated by task 12184:
kasan_save_stack (mm/kasan/common.c:48)
kasan_save_track (./arch/x86/include/asm/current.h:49 mm/kasan/common.c:60 mm/kasan/common.c:69)
__kasan_slab_alloc (mm/kasan/common.c:319 mm/kasan/common.c:345)
kmem_cache_alloc_noprof (mm/slub.c:4085 mm/slub.c:4134 mm/slub.c:4141)
copy_net_ns (net/core/net_namespace.c:421 net/core/net_namespace.c:480)
create_new_namespaces
---truncated---Show less |
In the Linux kernel, the following vulnerability has been resolved:
ALSA: control: Avoid WARN() for symlink errors
Using WARN() for showing the error of symlink creations don't give
more information than telling that s...Show moreIn the Linux kernel, the following vulnerability has been resolved:
ALSA: control: Avoid WARN() for symlink errors
Using WARN() for showing the error of symlink creations don't give
more information than telling that something goes wrong, since the
usual code path is a lregister callback from each control element
creation. More badly, the use of WARN() rather confuses fuzzer as if
it were serious issues.
This patch downgrades the warning messages to use the normal dev_err()
instead of WARN(). For making it clearer, add the function name to
the prefix, too.Show less |
In the Linux kernel, the following vulnerability has been resolved:
bnxt_en: Fix aggregation ID mask to prevent oops on 5760X chips
The 5760X (P7) chip's HW GRO/LRO interface is very similar to that of
the previous gen...Show moreIn the Linux kernel, the following vulnerability has been resolved:
bnxt_en: Fix aggregation ID mask to prevent oops on 5760X chips
The 5760X (P7) chip's HW GRO/LRO interface is very similar to that of
the previous generation (5750X or P5). However, the aggregation ID
fields in the completion structures on P7 have been redefined from
16 bits to 12 bits. The freed up 4 bits are redefined for part of the
metadata such as the VLAN ID. The aggregation ID mask was not modified
when adding support for P7 chips. Including the extra 4 bits for the
aggregation ID can potentially cause the driver to store or fetch the
packet header of GRO/LRO packets in the wrong TPA buffer. It may hit
the BUG() condition in __skb_pull() because the SKB contains no valid
packet header:
kernel BUG at include/linux/skbuff.h:2766!
Oops: invalid opcode: 0000 1 PREEMPT SMP NOPTI
CPU: 4 UID: 0 PID: 0 Comm: swapper/4 Kdump: loaded Tainted: G OE 6.12.0-rc2+ #7
Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: Dell Inc. PowerEdge R760/0VRV9X, BIOS 1.0.1 12/27/2022
RIP: 0010:eth_type_trans+0xda/0x140
Code: 80 00 00 00 eb c1 8b 47 70 2b 47 74 48 8b 97 d0 00 00 00 83 f8 01 7e 1b 48 85 d2 74 06 66 83 3a ff 74 09 b8 00 04 00 00 eb a5 <0f> 0b b8 00 01 00 00 eb 9c 48 85 ff 74 eb 31 f6 b9 02 00 00 00 48
RSP: 0018:ff615003803fcc28 EFLAGS: 00010283
RAX: 00000000000022d2 RBX: 0000000000000003 RCX: ff2e8c25da334040
RDX: 0000000000000040 RSI: ff2e8c25c1ce8000 RDI: ff2e8c25869f9000
RBP: ff2e8c258c31c000 R08: ff2e8c25da334000 R09: 0000000000000001
R10: ff2e8c25da3342c0 R11: ff2e8c25c1ce89c0 R12: ff2e8c258e0990b0
R13: ff2e8c25bb120000 R14: ff2e8c25c1ce89c0 R15: ff2e8c25869f9000
FS: 0000000000000000(0000) GS:ff2e8c34be300000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f05317e4c8 CR3: 000000108bac6006 CR4: 0000000000773ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<IRQ>
? die+0x33/0x90
? do_trap+0xd9/0x100
? eth_type_trans+0xda/0x140
? do_error_trap+0x65/0x80
? eth_type_trans+0xda/0x140
? exc_invalid_op+0x4e/0x70
? eth_type_trans+0xda/0x140
? asm_exc_invalid_op+0x16/0x20
? eth_type_trans+0xda/0x140
bnxt_tpa_end+0x10b/0x6b0 [bnxt_en]
? bnxt_tpa_start+0x195/0x320 [bnxt_en]
bnxt_rx_pkt+0x902/0xd90 [bnxt_en]
? __bnxt_tx_int.constprop.0+0x89/0x300 [bnxt_en]
? kmem_cache_free+0x343/0x440
? __bnxt_tx_int.constprop.0+0x24f/0x300 [bnxt_en]
__bnxt_poll_work+0x193/0x370 [bnxt_en]
bnxt_poll_p5+0x9a/0x300 [bnxt_en]
? try_to_wake_up+0x209/0x670
__napi_poll+0x29/0x1b0
Fix it by redefining the aggregation ID mask for P5_PLUS chips to be
12 bits. This will work because the maximum aggregation ID is less
than 4096 on all P5_PLUS chips.Show less |
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: do not defer rule destruction via call_rcu
nf_tables_chain_destroy can sleep, it can't be used from call_rcu
callbacks.
Moreove...Show moreIn the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: do not defer rule destruction via call_rcu
nf_tables_chain_destroy can sleep, it can't be used from call_rcu
callbacks.
Moreover, nf_tables_rule_release() is only safe for error unwinding,
while transaction mutex is held and the to-be-desroyed rule was not
exposed to either dataplane or dumps, as it deactives+frees without
the required synchronize_rcu() in-between.
nft_rule_expr_deactivate() callbacks will change ->use counters
of other chains/sets, see e.g. nft_lookup .deactivate callback, these
must be serialized via transaction mutex.
Also add a few lockdep asserts to make this more explicit.
Calling synchronize_rcu() isn't ideal, but fixing this without is hard
and way more intrusive. As-is, we can get:
WARNING: .. net/netfilter/nf_tables_api.c:5515 nft_set_destroy+0x..
Workqueue: events nf_tables_trans_destroy_work
RIP: 0010:nft_set_destroy+0x3fe/0x5c0
Call Trace:
<TASK>
nf_tables_trans_destroy_work+0x6b7/0xad0
process_one_work+0x64a/0xce0
worker_thread+0x613/0x10d0
In case the synchronize_rcu becomes an issue, we can explore alternatives.
One way would be to allocate nft_trans_rule objects + one nft_trans_chain
object, deactivate the rules + the chain and then defer the freeing to the
nft destroy workqueue. We'd still need to keep the synchronize_rcu path as
a fallback to handle -ENOMEM corner cases though.Show less |
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_event: Fix using rcu_read_(un)lock while iterating
The usage of rcu_read_(un)lock while inside list_for_each_entry_rcu is
not safe sinc...Show moreIn the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_event: Fix using rcu_read_(un)lock while iterating
The usage of rcu_read_(un)lock while inside list_for_each_entry_rcu is
not safe since for the most part entries fetched this way shall be
treated as rcu_dereference:
Note that the value returned by rcu_dereference() is valid
only within the enclosing RCU read-side critical section [1]_.
For example, the following is **not** legal::
rcu_read_lock();
p = rcu_dereference(head.next);
rcu_read_unlock();
x = p->address; /* BUG!!! */
rcu_read_lock();
y = p->data; /* BUG!!! */
rcu_read_unlock();Show less |
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btmtk: avoid UAF in btmtk_process_coredump
hci_devcd_append may lead to the release of the skb, so it cannot be
accessed once it is called....Show moreIn the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btmtk: avoid UAF in btmtk_process_coredump
hci_devcd_append may lead to the release of the skb, so it cannot be
accessed once it is called.
==================================================================
BUG: KASAN: slab-use-after-free in btmtk_process_coredump+0x2a7/0x2d0 [btmtk]
Read of size 4 at addr ffff888033cfabb0 by task kworker/0:3/82
CPU: 0 PID: 82 Comm: kworker/0:3 Tainted: G U 6.6.40-lockdep-03464-g1d8b4eb3060e #1 b0b3c1cc0c842735643fb411799d97921d1f688c
Hardware name: Google Yaviks_Ufs/Yaviks_Ufs, BIOS Google_Yaviks_Ufs.15217.552.0 05/07/2024
Workqueue: events btusb_rx_work [btusb]
Call Trace:
<TASK>
dump_stack_lvl+0xfd/0x150
print_report+0x131/0x780
kasan_report+0x177/0x1c0
btmtk_process_coredump+0x2a7/0x2d0 [btmtk 03edd567dd71a65958807c95a65db31d433e1d01]
btusb_recv_acl_mtk+0x11c/0x1a0 [btusb 675430d1e87c4f24d0c1f80efe600757a0f32bec]
btusb_rx_work+0x9e/0xe0 [btusb 675430d1e87c4f24d0c1f80efe600757a0f32bec]
worker_thread+0xe44/0x2cc0
kthread+0x2ff/0x3a0
ret_from_fork+0x51/0x80
ret_from_fork_asm+0x1b/0x30
</TASK>
Allocated by task 82:
stack_trace_save+0xdc/0x190
kasan_set_track+0x4e/0x80
__kasan_slab_alloc+0x4e/0x60
kmem_cache_alloc+0x19f/0x360
skb_clone+0x132/0xf70
btusb_recv_acl_mtk+0x104/0x1a0 [btusb]
btusb_rx_work+0x9e/0xe0 [btusb]
worker_thread+0xe44/0x2cc0
kthread+0x2ff/0x3a0
ret_from_fork+0x51/0x80
ret_from_fork_asm+0x1b/0x30
Freed by task 1733:
stack_trace_save+0xdc/0x190
kasan_set_track+0x4e/0x80
kasan_save_free_info+0x28/0xb0
____kasan_slab_free+0xfd/0x170
kmem_cache_free+0x183/0x3f0
hci_devcd_rx+0x91a/0x2060 [bluetooth]
worker_thread+0xe44/0x2cc0
kthread+0x2ff/0x3a0
ret_from_fork+0x51/0x80
ret_from_fork_asm+0x1b/0x30
The buggy address belongs to the object at ffff888033cfab40
which belongs to the cache skbuff_head_cache of size 232
The buggy address is located 112 bytes inside of
freed 232-byte region [ffff888033cfab40, ffff888033cfac28)
The buggy address belongs to the physical page:
page:00000000a174ba93 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x33cfa
head:00000000a174ba93 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x4000000000000840(slab|head|zone=1)
page_type: 0xffffffff()
raw: 4000000000000840 ffff888100848a00 0000000000000000 0000000000000001
raw: 0000000000000000 0000000080190019 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888033cfaa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc
ffff888033cfab00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
>ffff888033cfab80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888033cfac00: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc
ffff888033cfac80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
Check if we need to call hci_devcd_complete before calling
hci_devcd_append. That requires that we check data->cd_info.cnt >=
MTK_COREDUMP_NUM instead of data->cd_info.cnt > MTK_COREDUMP_NUM, as we
increment data->cd_info.cnt only once the call to hci_devcd_append
succeeds.Show less |
In the Linux kernel, the following vulnerability has been resolved:
drm/xe/reg_sr: Remove register pool
That pool implementation doesn't really work: if the krealloc happens to
move the memory and return another addres...Show moreIn the Linux kernel, the following vulnerability has been resolved:
drm/xe/reg_sr: Remove register pool
That pool implementation doesn't really work: if the krealloc happens to
move the memory and return another address, the entries in the xarray
become invalid, leading to use-after-free later:
BUG: KASAN: slab-use-after-free in xe_reg_sr_apply_mmio+0x570/0x760 [xe]
Read of size 4 at addr ffff8881244b2590 by task modprobe/2753
Allocated by task 2753:
kasan_save_stack+0x39/0x70
kasan_save_track+0x14/0x40
kasan_save_alloc_info+0x37/0x60
__kasan_kmalloc+0xc3/0xd0
__kmalloc_node_track_caller_noprof+0x200/0x6d0
krealloc_noprof+0x229/0x380
Simplify the code to fix the bug. A better pooling strategy may be added
back later if needed.
(cherry picked from commit e5283bd4dfecbd3335f43b62a68e24dae23f59e4)Show less |
In the Linux kernel, the following vulnerability has been resolved:
can: hi311x: hi3110_can_ist(): fix potential use-after-free
The commit a22bd630cfff ("can: hi311x: do not report txerr and rxerr
during bus-off") remo...Show moreIn the Linux kernel, the following vulnerability has been resolved:
can: hi311x: hi3110_can_ist(): fix potential use-after-free
The commit a22bd630cfff ("can: hi311x: do not report txerr and rxerr
during bus-off") removed the reporting of rxerr and txerr even in case
of correct operation (i. e. not bus-off).
The error count information added to the CAN frame after netif_rx() is
a potential use after free, since there is no guarantee that the skb
is in the same state. It might be freed or reused.
Fix the issue by postponing the netif_rx() call in case of txerr and
rxerr reporting.Show less |
In the Linux kernel, the following vulnerability has been resolved:
netfilter: x_tables: fix LED ID check in led_tg_check()
Syzbot has reported the following BUG detected by KASAN:
BUG: KASAN: slab-out-of-bounds in st...Show moreIn the Linux kernel, the following vulnerability has been resolved:
netfilter: x_tables: fix LED ID check in led_tg_check()
Syzbot has reported the following BUG detected by KASAN:
BUG: KASAN: slab-out-of-bounds in strlen+0x58/0x70
Read of size 1 at addr ffff8881022da0c8 by task repro/5879
...
Call Trace:
<TASK>
dump_stack_lvl+0x241/0x360
? __pfx_dump_stack_lvl+0x10/0x10
? __pfx__printk+0x10/0x10
? _printk+0xd5/0x120
? __virt_addr_valid+0x183/0x530
? __virt_addr_valid+0x183/0x530
print_report+0x169/0x550
? __virt_addr_valid+0x183/0x530
? __virt_addr_valid+0x183/0x530
? __virt_addr_valid+0x45f/0x530
? __phys_addr+0xba/0x170
? strlen+0x58/0x70
kasan_report+0x143/0x180
? strlen+0x58/0x70
strlen+0x58/0x70
kstrdup+0x20/0x80
led_tg_check+0x18b/0x3c0
xt_check_target+0x3bb/0xa40
? __pfx_xt_check_target+0x10/0x10
? stack_depot_save_flags+0x6e4/0x830
? nft_target_init+0x174/0xc30
nft_target_init+0x82d/0xc30
? __pfx_nft_target_init+0x10/0x10
? nf_tables_newrule+0x1609/0x2980
? nf_tables_newrule+0x1609/0x2980
? rcu_is_watching+0x15/0xb0
? nf_tables_newrule+0x1609/0x2980
? nf_tables_newrule+0x1609/0x2980
? __kmalloc_noprof+0x21a/0x400
nf_tables_newrule+0x1860/0x2980
? __pfx_nf_tables_newrule+0x10/0x10
? __nla_parse+0x40/0x60
nfnetlink_rcv+0x14e5/0x2ab0
? __pfx_validate_chain+0x10/0x10
? __pfx_nfnetlink_rcv+0x10/0x10
? __lock_acquire+0x1384/0x2050
? netlink_deliver_tap+0x2e/0x1b0
? __pfx_lock_release+0x10/0x10
? netlink_deliver_tap+0x2e/0x1b0
netlink_unicast+0x7f8/0x990
? __pfx_netlink_unicast+0x10/0x10
? __virt_addr_valid+0x183/0x530
? __check_object_size+0x48e/0x900
netlink_sendmsg+0x8e4/0xcb0
? __pfx_netlink_sendmsg+0x10/0x10
? aa_sock_msg_perm+0x91/0x160
? __pfx_netlink_sendmsg+0x10/0x10
__sock_sendmsg+0x223/0x270
____sys_sendmsg+0x52a/0x7e0
? __pfx_____sys_sendmsg+0x10/0x10
__sys_sendmsg+0x292/0x380
? __pfx___sys_sendmsg+0x10/0x10
? lockdep_hardirqs_on_prepare+0x43d/0x780
? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
? exc_page_fault+0x590/0x8c0
? do_syscall_64+0xb6/0x230
do_syscall_64+0xf3/0x230
entry_SYSCALL_64_after_hwframe+0x77/0x7f
...
</TASK>
Since an invalid (without '\0' byte at all) byte sequence may be passed
from userspace, add an extra check to ensure that such a sequence is
rejected as possible ID and so never passed to 'kstrdup()' and further.Show less |
In the Linux kernel, the following vulnerability has been resolved:
net: enetc: Do not configure preemptible TCs if SIs do not support
Both ENETC PF and VF drivers share enetc_setup_tc_mqprio() to configure
MQPRIO. And...Show moreIn the Linux kernel, the following vulnerability has been resolved:
net: enetc: Do not configure preemptible TCs if SIs do not support
Both ENETC PF and VF drivers share enetc_setup_tc_mqprio() to configure
MQPRIO. And enetc_setup_tc_mqprio() calls enetc_change_preemptible_tcs()
to configure preemptible TCs. However, only PF is able to configure
preemptible TCs. Because only PF has related registers, while VF does not
have these registers. So for VF, its hw->port pointer is NULL. Therefore,
VF will access an invalid pointer when accessing a non-existent register,
which will cause a crash issue. The simplified log is as follows.
root@ls1028ardb:~# tc qdisc add dev eno0vf0 parent root handle 100: \
mqprio num_tc 4 map 0 0 1 1 2 2 3 3 queues 1@0 1@1 1@2 1@3 hw 1
[ 187.290775] Unable to handle kernel paging request at virtual address 0000000000001f00
[ 187.424831] pc : enetc_mm_commit_preemptible_tcs+0x1c4/0x400
[ 187.430518] lr : enetc_mm_commit_preemptible_tcs+0x30c/0x400
[ 187.511140] Call trace:
[ 187.513588] enetc_mm_commit_preemptible_tcs+0x1c4/0x400
[ 187.518918] enetc_setup_tc_mqprio+0x180/0x214
[ 187.523374] enetc_vf_setup_tc+0x1c/0x30
[ 187.527306] mqprio_enable_offload+0x144/0x178
[ 187.531766] mqprio_init+0x3ec/0x668
[ 187.535351] qdisc_create+0x15c/0x488
[ 187.539023] tc_modify_qdisc+0x398/0x73c
[ 187.542958] rtnetlink_rcv_msg+0x128/0x378
[ 187.547064] netlink_rcv_skb+0x60/0x130
[ 187.550910] rtnetlink_rcv+0x18/0x24
[ 187.554492] netlink_unicast+0x300/0x36c
[ 187.558425] netlink_sendmsg+0x1a8/0x420
[ 187.606759] ---[ end trace 0000000000000000 ]---
In addition, some PFs also do not support configuring preemptible TCs,
such as eno1 and eno3 on LS1028A. It won't crash like it does for VFs,
but we should prevent these PFs from accessing these unimplemented
registers.Show less |
In the Linux kernel, the following vulnerability has been resolved:
net: hsr: avoid potential out-of-bound access in fill_frame_info()
syzbot is able to feed a packet with 14 bytes, pretending
it is a vlan one.
Since...Show moreIn the Linux kernel, the following vulnerability has been resolved:
net: hsr: avoid potential out-of-bound access in fill_frame_info()
syzbot is able to feed a packet with 14 bytes, pretending
it is a vlan one.
Since fill_frame_info() is relying on skb->mac_len already,
extend the check to cover this case.
BUG: KMSAN: uninit-value in fill_frame_info net/hsr/hsr_forward.c:709 [inline]
BUG: KMSAN: uninit-value in hsr_forward_skb+0x9ee/0x3b10 net/hsr/hsr_forward.c:724
fill_frame_info net/hsr/hsr_forward.c:709 [inline]
hsr_forward_skb+0x9ee/0x3b10 net/hsr/hsr_forward.c:724
hsr_dev_xmit+0x2f0/0x350 net/hsr/hsr_device.c:235
__netdev_start_xmit include/linux/netdevice.h:5002 [inline]
netdev_start_xmit include/linux/netdevice.h:5011 [inline]
xmit_one net/core/dev.c:3590 [inline]
dev_hard_start_xmit+0x247/0xa20 net/core/dev.c:3606
__dev_queue_xmit+0x366a/0x57d0 net/core/dev.c:4434
dev_queue_xmit include/linux/netdevice.h:3168 [inline]
packet_xmit+0x9c/0x6c0 net/packet/af_packet.c:276
packet_snd net/packet/af_packet.c:3146 [inline]
packet_sendmsg+0x91ae/0xa6f0 net/packet/af_packet.c:3178
sock_sendmsg_nosec net/socket.c:711 [inline]
__sock_sendmsg+0x30f/0x380 net/socket.c:726
__sys_sendto+0x594/0x750 net/socket.c:2197
__do_sys_sendto net/socket.c:2204 [inline]
__se_sys_sendto net/socket.c:2200 [inline]
__x64_sys_sendto+0x125/0x1d0 net/socket.c:2200
x64_sys_call+0x346a/0x3c30 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:4091 [inline]
slab_alloc_node mm/slub.c:4134 [inline]
kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4186
kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:587
__alloc_skb+0x363/0x7b0 net/core/skbuff.c:678
alloc_skb include/linux/skbuff.h:1323 [inline]
alloc_skb_with_frags+0xc8/0xd00 net/core/skbuff.c:6612
sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2881
packet_alloc_skb net/packet/af_packet.c:2995 [inline]
packet_snd net/packet/af_packet.c:3089 [inline]
packet_sendmsg+0x74c6/0xa6f0 net/packet/af_packet.c:3178
sock_sendmsg_nosec net/socket.c:711 [inline]
__sock_sendmsg+0x30f/0x380 net/socket.c:726
__sys_sendto+0x594/0x750 net/socket.c:2197
__do_sys_sendto net/socket.c:2204 [inline]
__se_sys_sendto net/socket.c:2200 [inline]
__x64_sys_sendto+0x125/0x1d0 net/socket.c:2200
x64_sys_call+0x346a/0x3c30 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+0x77/0x7fShow less |
In the Linux kernel, the following vulnerability has been resolved:
net: Fix icmp host relookup triggering ip_rt_bug
arp link failure may trigger ip_rt_bug while xfrm enabled, call trace is:
WARNING: CPU: 0 PID: 0 at...Show moreIn the Linux kernel, the following vulnerability has been resolved:
net: Fix icmp host relookup triggering ip_rt_bug
arp link failure may trigger ip_rt_bug while xfrm enabled, call trace is:
WARNING: CPU: 0 PID: 0 at net/ipv4/route.c:1241 ip_rt_bug+0x14/0x20
Modules linked in:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.12.0-rc6-00077-g2e1b3cc9d7f7
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:ip_rt_bug+0x14/0x20
Call Trace:
<IRQ>
ip_send_skb+0x14/0x40
__icmp_send+0x42d/0x6a0
ipv4_link_failure+0xe2/0x1d0
arp_error_report+0x3c/0x50
neigh_invalidate+0x8d/0x100
neigh_timer_handler+0x2e1/0x330
call_timer_fn+0x21/0x120
__run_timer_base.part.0+0x1c9/0x270
run_timer_softirq+0x4c/0x80
handle_softirqs+0xac/0x280
irq_exit_rcu+0x62/0x80
sysvec_apic_timer_interrupt+0x77/0x90
The script below reproduces this scenario:
ip xfrm policy add src 0.0.0.0/0 dst 0.0.0.0/0 \
dir out priority 0 ptype main flag localok icmp
ip l a veth1 type veth
ip a a 192.168.141.111/24 dev veth0
ip l s veth0 up
ping 192.168.141.155 -c 1
icmp_route_lookup() create input routes for locally generated packets
while xfrm relookup ICMP traffic.Then it will set input route
(dst->out = ip_rt_bug) to skb for DESTUNREACH.
For ICMP err triggered by locally generated packets, dst->dev of output
route is loopback. Generally, xfrm relookup verification is not required
on loopback interfaces (net.ipv4.conf.lo.disable_xfrm = 1).
Skip icmp relookup for locally generated packets to fix it.Show less |
In the Linux kernel, the following vulnerability has been resolved:
ipv6: avoid possible NULL deref in modify_prefix_route()
syzbot found a NULL deref [1] in modify_prefix_route(), caused by one
fib6_info without a fib...Show moreIn the Linux kernel, the following vulnerability has been resolved:
ipv6: avoid possible NULL deref in modify_prefix_route()
syzbot found a NULL deref [1] in modify_prefix_route(), caused by one
fib6_info without a fib6_table pointer set.
This can happen for net->ipv6.fib6_null_entry
[1]
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]
CPU: 1 UID: 0 PID: 5837 Comm: syz-executor888 Not tainted 6.12.0-syzkaller-09567-g7eef7e306d3c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:__lock_acquire+0xe4/0x3c40 kernel/locking/lockdep.c:5089
Code: 08 84 d2 0f 85 15 14 00 00 44 8b 0d ca 98 f5 0e 45 85 c9 0f 84 b4 0e 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 96 2c 00 00 49 8b 04 24 48 3d a0 07 7f 93 0f 84
RSP: 0018:ffffc900035d7268 EFLAGS: 00010006
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000006 RSI: 1ffff920006bae5f RDI: 0000000000000030
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff90608e17 R11: 0000000000000001 R12: 0000000000000030
R13: ffff888036334880 R14: 0000000000000000 R15: 0000000000000000
FS: 0000555579e90380(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc59cc4278 CR3: 0000000072b54000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
modify_prefix_route+0x30b/0x8b0 net/ipv6/addrconf.c:4831
inet6_addr_modify net/ipv6/addrconf.c:4923 [inline]
inet6_rtm_newaddr+0x12c7/0x1ab0 net/ipv6/addrconf.c:5055
rtnetlink_rcv_msg+0x3c7/0xea0 net/core/rtnetlink.c:6920
netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2541
netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline]
netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1347
netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1891
sock_sendmsg_nosec net/socket.c:711 [inline]
__sock_sendmsg net/socket.c:726 [inline]
____sys_sendmsg+0xaaf/0xc90 net/socket.c:2583
___sys_sendmsg+0x135/0x1e0 net/socket.c:2637
__sys_sendmsg+0x16e/0x220 net/socket.c:2669
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd1dcef8b79
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc59cc4378 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd1dcef8b79
RDX: 0000000000040040 RSI: 0000000020000140 RDI: 0000000000000004
RBP: 00000000000113fd R08: 0000000000000006 R09: 0000000000000006
R10: 0000000000000006 R11: 0000000000000246 R12: 00007ffc59cc438c
R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001
</TASK>Show less |
In the Linux kernel, the following vulnerability has been resolved:
can: j1939: j1939_session_new(): fix skb reference counting
Since j1939_session_skb_queue() does an extra skb_get() for each new
skb, do the same for...Show moreIn the Linux kernel, the following vulnerability has been resolved:
can: j1939: j1939_session_new(): fix skb reference counting
Since j1939_session_skb_queue() does an extra skb_get() for each new
skb, do the same for the initial one in j1939_session_new() to avoid
refcount underflow.
[mkl: clean up commit message]Show less |
In the Linux kernel, the following vulnerability has been resolved:
net/ipv6: release expired exception dst cached in socket
Dst objects get leaked in ip6_negative_advice() when this function is
executed for an expired...Show moreIn the Linux kernel, the following vulnerability has been resolved:
net/ipv6: release expired exception dst cached in socket
Dst objects get leaked in ip6_negative_advice() when this function is
executed for an expired IPv6 route located in the exception table. There
are several conditions that must be fulfilled for the leak to occur:
* an ICMPv6 packet indicating a change of the MTU for the path is received,
resulting in an exception dst being created
* a TCP connection that uses the exception dst for routing packets must
start timing out so that TCP begins retransmissions
* after the exception dst expires, the FIB6 garbage collector must not run
before TCP executes ip6_negative_advice() for the expired exception dst
When TCP executes ip6_negative_advice() for an exception dst that has
expired and if no other socket holds a reference to the exception dst, the
refcount of the exception dst is 2, which corresponds to the increment
made by dst_init() and the increment made by the TCP socket for which the
connection is timing out. The refcount made by the socket is never
released. The refcount of the dst is decremented in sk_dst_reset() but
that decrement is counteracted by a dst_hold() intentionally placed just
before the sk_dst_reset() in ip6_negative_advice(). After
ip6_negative_advice() has finished, there is no other object tied to the
dst. The socket lost its reference stored in sk_dst_cache and the dst is
no longer in the exception table. The exception dst becomes a leaked
object.
As a result of this dst leak, an unbalanced refcount is reported for the
loopback device of a net namespace being destroyed under kernels that do
not contain e5f80fcf869a ("ipv6: give an IPv6 dev to blackhole_netdev"):
unregister_netdevice: waiting for lo to become free. Usage count = 2
Fix the dst leak by removing the dst_hold() in ip6_negative_advice(). The
patch that introduced the dst_hold() in ip6_negative_advice() was
92f1655aa2b22 ("net: fix __dst_negative_advice() race"). But 92f1655aa2b22
merely refactored the code with regards to the dst refcount so the issue
was present even before 92f1655aa2b22. The bug was introduced in
54c1a859efd9f ("ipv6: Don't drop cache route entry unless timer actually
expired.") where the expired cached route is deleted and the sk_dst_cache
member of the socket is set to NULL by calling dst_negative_advice() but
the refcount belonging to the socket is left unbalanced.
The IPv4 version - ipv4_negative_advice() - is not affected by this bug.
When the TCP connection times out ipv4_negative_advice() merely resets the
sk_dst_cache of the socket while decrementing the refcount of the
exception dst.Show less |