In the Linux kernel, the following vulnerability has been resolved:
dm mpath: Add missing dm_put_device when failing to get scsi dh name
When commit fd81bc5cca8f ("scsi: device_handler: Return error pointer in
scsi_dh_attached_handler_name()") added code to fail parsing the path if
scsi_dh_attached_handler_name() failed with -ENOMEM, it didn't clean up
the reference to the path device that had just been taken. Fix this, and
steamline the error paths of parse_path() a little.
In the Linux kernel, the following vulnerability has been resolved:
nfsd: fix nfs4_file refcount leak in nfsd_get_dir_deleg()
Claude pointed out that there is a nfs4_file refcount leak in
nfsd_get_dir_deleg(). Ensure that the reference to "fp" is released
before returning.
In the Linux kernel, the following vulnerability has been resolved:
net: consume xmit errors of GSO frames
udpgro_frglist.sh and udpgro_bench.sh are the flakiest tests
currently in NIPA. They fail in the same exact way, TCP GRO
test stalls occasionally and the test gets killed after 10min.
These tests use veth to simulate GRO. They attach a trivial
("return XDP_PASS;") XDP program to the veth to force TSO off
and NAPI on.
Digging into the failure mode we can see that the connection
is completely stuck after a burst of drops. The sender's snd_nxt
is at sequence number N [1], but the receiver claims to have
received (rcv_nxt) up to N + 3 * MSS [2]. Last piece of the puzzle
is that senders rtx queue is not empty (let's say the block in
the rtx queue is at sequence number N - 4 * MSS [3]).
In this state, sender sends a retransmission from the rtx queue
with a single segment, and sequence numbers N-4*MSS:N-3*MSS [3].
Receiver sees it and responds with an ACK all the way up to
N + 3 * MSS [2]. But sender will reject this ack as TCP_ACK_UNSENT_DATA
because it has no recollection of ever sending data that far out [1].
And we are stuck.
The root cause is the mess of the xmit return codes. veth returns
an error when it can't xmit a frame. We end up with a loss event
like this:
-------------------------------------------------
| GSO super frame 1 | GSO super frame 2 |
|-----------------------------------------------|
| seg | seg | seg | seg | seg | seg | seg | seg |
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
-------------------------------------------------
x ok ok <ok>| ok ok ok <x>
\\
snd_nxt
"x" means packet lost by veth, and "ok" means it went thru.
Since veth has TSO disabled in this test it sees individual segments.
Segment 1 is on the retransmit queue and will be resent.
So why did the sender not advance snd_nxt even tho it clearly did
send up to seg 8? tcp_write_xmit() interprets the return code
from the core to mean that data has not been sent at all. Since
TCP deals with GSO super frames, not individual segment the crux
of the problem is that loss of a single segment can be interpreted
as loss of all. TCP only sees the last return code for the last
segment of the GSO frame (in <> brackets in the diagram above).
Of course for the problem to occur we need a setup or a device
without a Qdisc. Otherwise Qdisc layer disconnects the protocol
layer from the device errors completely.
We have multiple ways to fix this.
1) make veth not return an error when it lost a packet.
While this is what I think we did in the past, the issue keeps
reappearing and it's annoying to debug. The game of whack
a mole is not great.
2) fix the damn return codes
We only talk about NETDEV_TX_OK and NETDEV_TX_BUSY in the
documentation, so maybe we should make the return code from
ndo_start_xmit() a boolean. I like that the most, but perhaps
some ancient, not-really-networking protocol would suffer.
3) make TCP ignore the errors
It is not entirely clear to me what benefit TCP gets from
interpreting the result of ip_queue_xmit()? Specifically once
the connection is established and we're pushing data - packet
loss is just packet loss?
4) this fix
Ignore the rc in the Qdisc-less+GSO case, since it's unreliable.
We already always return OK in the TCQ_F_CAN_BYPASS case.
In the Qdisc-less case let's be a bit more conservative and only
mask the GSO errors. This path is taken by non-IP-"networks"
like CAN, MCTP etc, so we could regress some ancient thing.
This is the simplest, but also maybe the hackiest fix?
Similar fix has been proposed by Eric in the past but never committed
because original reporter was working with an OOT driver and wasn't
providing feedback (see Link).
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: validate user queue size constraints
Add validation to ensure user queue sizes meet hardware requirements:
- Size must be a power of two for efficient ring buffer wrapping
- Size must be at least AMDGPU_GPU_PAGE_SIZE to prevent undersized allocations
This prevents invalid configurations that could lead to GPU faults or
unexpected behavior.
In the Linux kernel, the following vulnerability has been resolved:
soc: ti: pruss: Fix double free in pruss_clk_mux_setup()
In the pruss_clk_mux_setup(), the devm_add_action_or_reset() indirectly
calls pruss_of_free_clk_provider(), which calls of_node_put(clk_mux_np)
on the error path. However, after the devm_add_action_or_reset()
returns, the of_node_put(clk_mux_np) is called again, causing a double
free.
Fix by returning directly, to avoid the duplicate of_node_put().
In the Linux kernel, the following vulnerability has been resolved:
netconsole: avoid OOB reads, msg is not nul-terminated
msg passed to netconsole from the console subsystem is not guaranteed
to be nul-terminated. Before recent
commit 7eab73b18630 ("netconsole: convert to NBCON console infrastructure")
the message would be placed in printk_shared_pbufs, a static global
buffer, so KASAN had harder time catching OOB accesses. Now we see:
printk: console [netcon_ext0] enabled
BUG: KASAN: slab-out-of-bounds in string+0x1f7/0x240
Read of size 1 at addr ffff88813b6d4c00 by task pr/netcon_ext0/594
CPU: 65 UID: 0 PID: 594 Comm: pr/netcon_ext0 Not tainted 6.19.0-11754-g4246fd6547c9
Call Trace:
kasan_report+0xe4/0x120
string+0x1f7/0x240
vsnprintf+0x655/0xba0
scnprintf+0xba/0x120
netconsole_write+0x3fe/0xa10
nbcon_emit_next_record+0x46e/0x860
nbcon_kthread_func+0x623/0x750
Allocated by task 1:
nbcon_alloc+0x1ea/0x450
register_console+0x26b/0xe10
init_netconsole+0xbb0/0xda0
The buggy address belongs to the object at ffff88813b6d4000
which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 0 bytes to the right of
allocated 3072-byte region [ffff88813b6d4000, ffff88813b6d4c00)
In the Linux kernel, the following vulnerability has been resolved:
tcp: fix potential race in tcp_v6_syn_recv_sock()
Code in tcp_v6_syn_recv_sock() after the call to tcp_v4_syn_recv_sock()
is done too late.
After tcp_v4_syn_recv_sock(), the child socket is already visible
from TCP ehash table and other cpus might use it.
Since newinet->pinet6 is still pointing to the listener ipv6_pinfo
bad things can happen as syzbot found.
Move the problematic code in tcp_v6_mapped_child_init()
and call this new helper from tcp_v4_syn_recv_sock() before
the ehash insertion.
This allows the removal of one tcp_sync_mss(), since
tcp_v4_syn_recv_sock() will call it with the correct
context.
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Fix "scheduling while atomic" in IPsec MAC address query
Fix a "scheduling while atomic" bug in mlx5e_ipsec_init_macs() by
replacing mlx5_query_mac_address() with ether_addr_copy() to get the
local MAC address directly from netdev->dev_addr.
The issue occurs because mlx5_query_mac_address() queries the hardware
which involves mlx5_cmd_exec() that can sleep, but it is called from
the mlx5e_ipsec_handle_event workqueue which runs in atomic context.
The MAC address is already available in netdev->dev_addr, so no need
to query hardware. This avoids the sleeping call and resolves the bug.
Call trace:
BUG: scheduling while atomic: kworker/u112:2/69344/0x00000200
__schedule+0x7ab/0xa20
schedule+0x1c/0xb0
schedule_timeout+0x6e/0xf0
__wait_for_common+0x91/0x1b0
cmd_exec+0xa85/0xff0 [mlx5_core]
mlx5_cmd_exec+0x1f/0x50 [mlx5_core]
mlx5_query_nic_vport_mac_address+0x7b/0xd0 [mlx5_core]
mlx5_query_mac_address+0x19/0x30 [mlx5_core]
mlx5e_ipsec_init_macs+0xc1/0x720 [mlx5_core]
mlx5e_ipsec_build_accel_xfrm_attrs+0x422/0x670 [mlx5_core]
mlx5e_ipsec_handle_event+0x2b9/0x460 [mlx5_core]
process_one_work+0x178/0x2e0
worker_thread+0x2ea/0x430
In the Linux kernel, the following vulnerability has been resolved:
rnbd-srv: Zero the rsp buffer before using it
Before using the data buffer to send back the response message, zero it
completely. This prevents any stray bytes to be picked up by the client
side when there the message is exchanged between different protocol
versions.
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix signededness bug in smb_direct_prepare_negotiation()
smb_direct_prepare_negotiation() casts an unsigned __u32 value
from sp->max_recv_size and req->preferred_send_size to a signed
int before computing min_t(int, ...). A maliciously provided
preferred_send_size of 0x80000000 will return as smaller than
max_recv_size, and then be used to set the maximum allowed
alowed receive size for the next message.
By sending a second message with a large value (>1420 bytes)
the attacker can then achieve a heap buffer overflow.
This fix replaces min_t(int, ...) with min_t(u32)