btrfs: zstd: fix lost wakeup when waiting for a workspace
In the Linux kernel, the following vulnerability has been resolved:
btrfs: zstd: fix lost wakeup when waiting for a workspace
A writer can sleep forever in zstd_get_workspace() even though a workspace
is free. When zstd_alloc_workspace() fails, the task is queued on
zwsm->wait and schedules unconditionally, never re-testing the pool.
zstd_put_workspace() publishes the workspace and then calls cond_wake_up(),
which only wakes when a sleeper is already visible, so a workspace returned
between the failed allocation and prepare_to_wait() wakes nobody. The
window is wide: zstd_alloc_workspace() goes through kvmalloc() and may
enter reclaim.
O
In the Linux kernel, the following vulnerability has been resolved:
ipvs: fix reversed sequence option serialization
hton_seq() expects the host-order source first and the unaligned
network-order destination second. The version 1 sync sender passes these
arguments in reverse for both sequence blocks. This leaves 24 bytes of the
kmalloc-backed message unwritten. It may disclose stale heap data and
replace the live connection sequence state with values read from the
buffer.
Pass the connection sequence state as the source and the message payload as
the destination for both blocks.
netfilter: nf_conntrack_sip: fix OOB read in sip_skip_whitespace()
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack_sip: fix OOB read in sip_skip_whitespace()
sip_skip_whitespace() returns dptr unchanged when its own loop
exhausts the buffer (dptr == limit), instead of NULL like its sibling
sip_follow_continuation() returns on its own "no more data" path.
ct_sip_get_header() only checks for NULL after calling it:
dptr = sip_skip_whitespace(dptr, limit);
if (dptr == NULL)
break;
if (*dptr != ':' || ++dptr >= limit)
break;
so a recognized header name followed only by spaces/tabs running to
the exact end of the SIP payload, with no colon,
tracing/probes: Fix use-after-free on field name/type of events with multiple probes
In the Linux kernel, the following vulnerability has been resolved:
tracing/probes: Fix use-after-free on field name/type of events with multiple probes
The fields of a probe-based dynamic event (kprobe, uprobe, eprobe and
fprobe events) are created in traceprobe_define_arg_fields() by handing
the probe_arg name/type strings to trace_define_field(), which only
stores the pointers without copying. Those strings are owned by the
trace_probe and are freed when that probe is removed.
An event can have several probes attached. The field list is defined
only once, by the first probe that registers the event, but it is kept
alive by any surviving
bpf: reject BPF_PSEUDO_FUNC reference to the main program
In the Linux kernel, the following vulnerability has been resolved:
bpf: reject BPF_PSEUDO_FUNC reference to the main program
fixups.c:jit_subprogs() rewrites BPF_PSEUDO_FUNC loads to contain real
function addresses. This function is invoked from bpf_jit_subprogs()
only when env->subprog_cnt > 1. Meaning that for any program like
below:
int main(void *ctx) {
void *ptr = main;
...
bpf_timer_set_callback(..., ptr);
...
}
The 'ptr' won't be ever converted to contain an address.
In combination with e.g. bpf_timer_set_callback() this would lead to a
function call at a bogus address.
Instead of complicating the implementati
bonding: do not clear curr_active_slave prematurely when releasing all slaves
In the Linux kernel, the following vulnerability has been resolved:
bonding: do not clear curr_active_slave prematurely when releasing all slaves
When releasing all slaves during bond destruction (all == true),
__bond_release_one() unconditionally clears bond->curr_active_slave to
NULL in every iteration.
If a backup slave is released before the active slave,
bond_alb_deinit_slave() triggers rlb_teach_disabled_mac_on_primary(),
which increments the active slave dev promiscuity counter and sets
bond_info->primary_is_promisc = 1.
Because bond->curr_active_slave was prematurely cleared to NULL when
releasing the backup slave, the subsequent
net: Remove conflicting altnames for dying netns in __dev_change_net_namespace().
In the Linux kernel, the following vulnerability has been resolved:
net: Remove conflicting altnames for dying netns in __dev_change_net_namespace().
syzbot reported the warning in cfg80211_pernet_exit(). [0]
The repro does the following:
1. create two device in root netns and non-root netns
2. assign the same altname for the two devices
3. remove the non-root netns
Since commit 7663d522099e ("net: check for altname conflicts
when changing netdev's netns"), cfg80211_switch_netns() and
cfg802154_switch_netns() fail if init_net has a device with the
conflicting altname.
default_device_exit_net() had the same issue and commit d09486a
net/rds: clear cp_flags bits individually in rds_conn_path_reset()
In the Linux kernel, the following vulnerability has been resolved:
net/rds: clear cp_flags bits individually in rds_conn_path_reset()
rds_conn_path_reset() wipes the whole flag word with a plain
cp->cp_flags = 0 store. Every other accessor of that word uses
atomic bitops, and some of them can run concurrently with the reset:
RDS_LL_SEND_FULL is set from rds_send_xmit() and cleared from the
transport completion paths, neither of which holds anything that
excludes the shutdown worker. A plain store racing an atomic
read-modify-write on the same word is a data race, and whichever
side loses has its update silently discarded.
Clear the two
net/rds: acquire RDS_IN_XMIT in rds_tcp_reset_callbacks()
In the Linux kernel, the following vulnerability has been resolved:
net/rds: acquire RDS_IN_XMIT in rds_tcp_reset_callbacks()
rds_tcp_reset_callbacks() quiesces the transmit path by setting the
path state to RDS_CONN_RESETTING and then waiting for RDS_IN_XMIT to
be sampled clear before swapping the underlying socket and calling
rds_send_path_reset().
Sampling the bit clear is not the same as owning it: rds_send_xmit()
can re-acquire RDS_IN_XMIT right after the wait_event() returns. Its
state recheck after taking the lock is a store-buffering pattern (the
resetter writes the state and reads the bit, the sender writes the
bit and reads the
net/rds: acquire the fastpath locks in rds_conn_shutdown()
In the Linux kernel, the following vulnerability has been resolved:
net/rds: acquire the fastpath locks in rds_conn_shutdown()
rds_conn_shutdown() quiesces the transmit and receive-refill paths by
waiting for RDS_IN_XMIT and RDS_RECV_REFILL to be sampled clear, and
then runs the transport shutdown and rds_conn_path_reset(). Sampling
the bits clear is not the same as owning them: the moment after the
wait_event() returns, rds_send_xmit() can re-acquire RDS_IN_XMIT (or
rds_ib_recv_refill() can re-acquire RDS_RECV_REFILL) and run
concurrently with the teardown.
The sender does recheck the connection state after taking the lock,
but that rech
net/rds: don't let rds_conn_shutdown() consume a concurrent drop
In the Linux kernel, the following vulnerability has been resolved:
net/rds: don't let rds_conn_shutdown() consume a concurrent drop
rds_conn_shutdown() finishes by moving the path from
RDS_CONN_DISCONNECTING to RDS_CONN_DOWN, and also accepts
RDS_CONN_ERROR as the starting state of that final transition, so that
a FIN processed in softirq context during the teardown does not derail
the shutdown into a noisy error path.
But consuming that RDS_CONN_ERROR also consumes the shutdown pass that
came with it: rds_conn_path_drop() sets RDS_CONN_ERROR and then queues
cp_down_w, and a pass that starts on a path already in RDS_CONN_DOWN
is a no-op.
In the Linux kernel, the following vulnerability has been resolved:
erofs: disable LZ4 rolling decompression for now
LZ4 rolling decompression [1] was introduced to reduce the memory
footprint of temporary pages:
For many cases, it is needed for users to read small data within
a compressed extent (pcluster), either due to random small read, or
since uptodate folios (typically order-0) cannot be reused for
decompression again since decompression algorithm refills
already-uptodate folios.
Rolling decompression works because LZ4 is LZ77-based and only refers
to the most recent 64 KiB of decompressed data, so in theory only a
bounded rol
bpf: Fix NULL-ptr-deref when showing a void BTF type
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix NULL-ptr-deref when showing a void BTF type
btf_modifier_show() resolves the modifier and then calls
btf_type_ops(t)->show() unconditionally. For the void type (type_id 0,
BTF_KIND_UNKN) kind_ops[] has no entry, so ->show is NULL.
A "const void" (a modifier resolving to void) cannot be a map key or
value - map_check_btf() rejects it because void has no size - so the map
dump path does not reach it. But bpf_snprintf_btf() takes a type_id
straight from the BPF program, and passing such a "const void" from the
vmlinux BTF NULL-derefs:
KASAN: null-ptr-deref in range
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix NULL-ptr-deref in btf_var_show()
btf_var_show() calls btf_type_id_resolve() unconditionally, which
dereferences btf->resolved_ids. That is NULL for a base BTF - e.g. the
vmlinux BTF that bpf_snprintf_btf() renders against - since base BTF is
not resolved during parsing. btf_modifier_show() guards this with
'if (btf->resolved_ids)', but btf_var_show() does not.
A BPF program that passes the type_id of a BTF_KIND_VAR from the vmlinux
BTF to bpf_snprintf_btf() thus NULL-derefs:
KASAN: probably user-memory-access in range [0x46638-0x4663f]
RIP: 0010:btf_var_show (ker
In the Linux kernel, the following vulnerability has been resolved:
bpf: Mark syscall helpers as sleepable
bpf_sys_bpf() executes the bpf(2) syscall body, which can take mutexes,
allocate with GFP_KERNEL, and wait for an RCU grace period.
bpf_sys_close() reaches close_fd() and filp_close(), which can sleep as
well.
Both helpers are limited to BPF_PROG_TYPE_SYSCALL, whose main program is
sleepable. That does not make every callback sleepable: a syscall program
can register a bpf_timer callback, and the verifier checks that callback
in a non-sleepable context while retaining the syscall helper set.
Without .might_sleep on the prototypes, su
nvme: remove stale namespaces by NSID range during scan
In the Linux kernel, the following vulnerability has been resolved:
nvme: remove stale namespaces by NSID range during scan
nvme_scan_ns_list() drops the stale namespaces in each gap in the
reported NSID list one NSID at a time. Every iteration calls
nvme_find_get_ns() to look the namespace up and removes it if it is
present. The loop runs once per NSID in the gap rather than once per
namespace actually present.
NSIDs are 32-bit, so a target with a sparse NSID space can make a
single gap spin the loop billions of times with nothing to remove.
watchdog: BUG: soft lockup - CPU#4 stuck for 26s!
Workqueue: nvme-wq nvme_scan_work [nvme_cor
bpf: Mark bpf_btf_find_by_name_kind() as sleepable
In the Linux kernel, the following vulnerability has been resolved:
bpf: Mark bpf_btf_find_by_name_kind() as sleepable
When bpf_btf_find_by_name_kind() finds a type in module BTF, it
returns a new BTF object fd through __btf_new_fd(). This reaches
anon_inode_getfd(), which can sleep while allocating or expanding the
current task fd table.
The helper prototype does not set might_sleep, so the verifier allows
the helper in non-sleepable contexts such as BPF timer callbacks. The
fd allocation can then sleep in softirq context and install the fd into
the interrupted task.
Mark the helper as sleepable. This preserves calls from the main body
o
bpf: Don't infer non-NULL from a pointer with an unbounded offset
In the Linux kernel, the following vulnerability has been resolved:
bpf: Don't infer non-NULL from a pointer with an unbounded offset
reg_not_null() decides that a register holds a non-NULL value by
looking at its type alone. For pointer types that allow arithmetic the
type only guarantees a non-NULL base, in case of an unbound offset
the runtime offset value might still add up to NULL.
Consider the followng program:
r6 = bpf_map_lookup_elem(map, &0); /* present */
if (r6 == 0) return 0;
r7 = bpf_map_lookup_elem(map, &1); /* absent, NULL at runtime */
r8 = r7;
r8 -= r6; /* pointer - pointer: unknown scalar, -r6 */
r8 <<=
bpf: Don't predict JMP32 pointer vs zero comparisons
In the Linux kernel, the following vulnerability has been resolved:
bpf: Don't predict JMP32 pointer vs zero comparisons
Consider the following program:
r1 = map_value; /* low 32 bits are zero at runtime */
r6 = 0xdead000000000000;
if w1 != 0 goto l1;
l0: r1 += r6;
r2 = *(u64 *)(r1 + 0);
exit;
l1: r6 = 0;
goto l0;
At the moment is_branch_taken() reports the jump as always taken,
because it does not distinguish between BPF_JMP and BPF_JMP32
comparisons when processing 'if w1 != 0 ...'.
bpf: Preserve inner map identity in callback frames
In the Linux kernel, the following vulnerability has been resolved:
bpf: Preserve inner map identity in callback frames
Callback frame constructors initialize map-typed argument registers with
__mark_reg_known_zero() and then restore map_ptr. This clears map_uid,
which is the only field distinguishing inner maps that share an
inner_map_meta template.
When a timer callback invokes bpf_for_each_map_elem() on a second inner
map, both the saved first map and the second map value can reach the nested
callback as the same template with map_uid zero. bpf_timer_init() then
accepts pairing the timer from the second map with the first map.
The runt