In the Linux kernel, the following vulnerability has been resolved:
bpf: Prevent tail call between progs attached to different hooks
bpf progs can be attached to kernel functions, and the attached functions
can take different parameters or return different return values. If
prog attached to one kernel function tail calls prog attached to another
kernel function, the ctx access or return value verification could be
bypassed.
For example, if prog1 is attached to func1 which takes only 1 parameter
and prog2 is attached to func2 which takes two parameters. Since verifier
assumes the bpf ctx passed to prog2 is constructed based on func2's
prototype, verifier allows prog2 to access the second parameter from
the bpf ctx passed to it. The problem is that verifier does not prevent
prog1 from passing its bpf ctx to prog2 via tail call. In this case,
the bpf ctx passed to prog2 is constructed from func1 instead of func2,
that is, the assumption for ctx access verification is bypassed.
Another example, if BPF LSM prog1 is attached to hook file_alloc_security,
and BPF LSM prog2 is attached to hook bpf_lsm_audit_rule_known. Verifier
knows the return value rules for these two hooks, e.g. it is legal for
bpf_lsm_audit_rule_known to return positive number 1, and it is illegal
for file_alloc_security to return positive number. So verifier allows
prog2 to return positive number 1, but does not allow prog1 to return
positive number. The problem is that verifier does not prevent prog1
from calling prog2 via tail call. In this case, prog2's return value 1
will be used as the return value for prog1's hook file_alloc_security.
That is, the return value rule is bypassed.
This patch adds restriction for tail call to prevent such bypasses.
In the Linux kernel, the following vulnerability has been resolved:
i40e: Fix macvlan leak by synchronizing access to mac_filter_hash
This patch addresses a macvlan leak issue in the i40e driver caused by
concurrent access to vsi->mac_filter_hash. The leak occurs when multiple
threads attempt to modify the mac_filter_hash simultaneously, leading to
inconsistent state and potential memory leaks.
To fix this, we now wrap the calls to i40e_del_mac_filter() and zeroing
vf->default_lan_addr.addr with spin_lock/unlock_bh(&vsi->mac_filter_hash_lock),
ensuring atomic operations and preventing concurrent access.
Additionally, we add lockdep_assert_held(&vsi->mac_filter_hash_lock) in
i40e_add_mac_filter() to help catch similar issues in the future.
Reproduction steps:
1. Spawn VFs and configure port vlan on them.
2. Trigger concurrent macvlan operations (e.g., adding and deleting
portvlan and/or mac filters).
3. Observe the potential memory leak and inconsistent state in the
mac_filter_hash.
This synchronization ensures the integrity of the mac_filter_hash and prevents
the described leak.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: RFCOMM: FIX possible deadlock in rfcomm_sk_state_change
rfcomm_sk_state_change attempts to use sock_lock so it must never be
called with it locked but rfcomm_sock_ioctl always attempt to lock it
causing the following trace:
======================================================
WARNING: possible circular locking dependency detected
6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted
------------------------------------------------------
syz-executor386/5093 is trying to acquire lock:
ffff88807c396258 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1671 [inline]
ffff88807c396258 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: rfcomm_sk_state_change+0x5b/0x310 net/bluetooth/rfcomm/sock.c:73
but task is already holding lock:
ffff88807badfd28 (&d->lock){+.+.}-{3:3}, at: __rfcomm_dlc_close+0x226/0x6a0 net/bluetooth/rfcomm/core.c:491
In the Linux kernel, the following vulnerability has been resolved:
netfilter: br_netfilter: fix panic with metadata_dst skb
Fix a kernel panic in the br_netfilter module when sending untagged
traffic via a VxLAN device.
This happens during the check for fragmentation in br_nf_dev_queue_xmit.
It is dependent on:
1) the br_netfilter module being loaded;
2) net.bridge.bridge-nf-call-iptables set to 1;
3) a bridge with a VxLAN (single-vxlan-device) netdevice as a bridge port;
4) untagged frames with size higher than the VxLAN MTU forwarded/flooded
When forwarding the untagged packet to the VxLAN bridge port, before
the netfilter hooks are called, br_handle_egress_vlan_tunnel is called and
changes the skb_dst to the tunnel dst. The tunnel_dst is a metadata type
of dst, i.e., skb_valid_dst(skb) is false, and metadata->dst.dev is NULL.
Then in the br_netfilter hooks, in br_nf_dev_queue_xmit, there's a check
for frames that needs to be fragmented: frames with higher MTU than the
VxLAN device end up calling br_nf_ip_fragment, which in turns call
ip_skb_dst_mtu.
The ip_dst_mtu tries to use the skb_dst(skb) as if it was a valid dst
with valid dst->dev, thus the crash.
This case was never supported in the first place, so drop the packet
instead.
PING 10.0.0.2 (10.0.0.2) from 0.0.0.0 h1-eth0: 2000(2028) bytes of data.
[ 176.291791] Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000110
[ 176.292101] Mem abort info:
[ 176.292184] ESR = 0x0000000096000004
[ 176.292322] EC = 0x25: DABT (current EL), IL = 32 bits
[ 176.292530] SET = 0, FnV = 0
[ 176.292709] EA = 0, S1PTW = 0
[ 176.292862] FSC = 0x04: level 0 translation fault
[ 176.293013] Data abort info:
[ 176.293104] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[ 176.293488] CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[ 176.293787] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[ 176.293995] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000043ef5000
[ 176.294166] [0000000000000110] pgd=0000000000000000,
p4d=0000000000000000
[ 176.294827] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[ 176.295252] Modules linked in: vxlan ip6_udp_tunnel udp_tunnel veth
br_netfilter bridge stp llc ipv6 crct10dif_ce
[ 176.295923] CPU: 0 PID: 188 Comm: ping Not tainted
6.8.0-rc3-g5b3fbd61b9d1 #2
[ 176.296314] Hardware name: linux,dummy-virt (DT)
[ 176.296535] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS
BTYPE=--)
[ 176.296808] pc : br_nf_dev_queue_xmit+0x390/0x4ec [br_netfilter]
[ 176.297382] lr : br_nf_dev_queue_xmit+0x2ac/0x4ec [br_netfilter]
[ 176.297636] sp : ffff800080003630
[ 176.297743] x29: ffff800080003630 x28: 0000000000000008 x27:
ffff6828c49ad9f8
[ 176.298093] x26: ffff6828c49ad000 x25: 0000000000000000 x24:
00000000000003e8
[ 176.298430] x23: 0000000000000000 x22: ffff6828c4960b40 x21:
ffff6828c3b16d28
[ 176.298652] x20: ffff6828c3167048 x19: ffff6828c3b16d00 x18:
0000000000000014
[ 176.298926] x17: ffffb0476322f000 x16: ffffb7e164023730 x15:
0000000095744632
[ 176.299296] x14: ffff6828c3f1c880 x13: 0000000000000002 x12:
ffffb7e137926a70
[ 176.299574] x11: 0000000000000001 x10: ffff6828c3f1c898 x9 :
0000000000000000
[ 176.300049] x8 : ffff6828c49bf070 x7 : 0008460f18d5f20e x6 :
f20e0100bebafeca
[ 176.300302] x5 : ffff6828c7f918fe x4 : ffff6828c49bf070 x3 :
0000000000000000
[ 176.300586] x2 : 0000000000000000 x1 : ffff6828c3c7ad00 x0 :
ffff6828c7f918f0
[ 176.300889] Call trace:
[ 176.301123] br_nf_dev_queue_xmit+0x390/0x4ec [br_netfilter]
[ 176.301411] br_nf_post_routing+0x2a8/0x3e4 [br_netfilter]
[ 176.301703] nf_hook_slow+0x48/0x124
[ 176.302060] br_forward_finish+0xc8/0xe8 [bridge]
[ 176.302371] br_nf_hook_thresh+0x124/0x134 [br_netfilter]
[ 176.302605] br_nf_forward_finish+0x118/0x22c [br_netfilter]
[ 176.302824] br_nf_forward_ip.part.0+0x264/0x290 [br_netfilter]
[ 176.303136] br_nf_forward+0x2b8/0x4e0 [br_netfilter]
[ 176.303359] nf_hook_slow+0x48/0x124
[ 176.303
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
fbcon: Fix a NULL pointer dereference issue in fbcon_putcs
syzbot has found a NULL pointer dereference bug in fbcon.
Here is the simplified C reproducer:
struct param {
uint8_t type;
struct tiocl_selection ts;
};
int main()
{
struct fb_con2fbmap con2fb;
struct param param;
int fd = open("/dev/fb1", 0, 0);
con2fb.console = 0x19;
con2fb.framebuffer = 0;
ioctl(fd, FBIOPUT_CON2FBMAP, &con2fb);
param.type = 2;
param.ts.xs = 0; param.ts.ys = 0;
param.ts.xe = 0; param.ts.ye = 0;
param.ts.sel_mode = 0;
int fd1 = open("/dev/tty1", O_RDWR, 0);
ioctl(fd1, TIOCLINUX, ¶m);
con2fb.console = 1;
con2fb.framebuffer = 0;
ioctl(fd, FBIOPUT_CON2FBMAP, &con2fb);
return 0;
}
After calling ioctl(fd1, TIOCLINUX, ¶m), the subsequent ioctl(fd, FBIOPUT_CON2FBMAP, &con2fb)
causes the kernel to follow a different execution path:
set_con2fb_map
-> con2fb_init_display
-> fbcon_set_disp
-> redraw_screen
-> hide_cursor
-> clear_selection
-> highlight
-> invert_screen
-> do_update_region
-> fbcon_putcs
-> ops->putcs
Since ops->putcs is a NULL pointer, this leads to a kernel panic.
To prevent this, we need to call set_blitting_type() within set_con2fb_map()
to properly initialize ops->putcs.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Check null pointer before dereferencing se
[WHAT & HOW]
se is null checked previously in the same function, indicating
it might be null; therefore, it must be checked when used again.
This fixes 1 FORWARD_NULL issue reported by Coverity.
In the Linux kernel, the following vulnerability has been resolved:
driver core: bus: Fix double free in driver API bus_register()
For bus_register(), any error which happens after kset_register() will
cause that @priv are freed twice, fixed by setting @priv with NULL after
the first free.