In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: bnep: pin L2CAP connection during netdev registration
bnep_add_connection() reads the L2CAP connection without holding the
channel lock, then passes its HCI device to register_netdev(). Controller
teardown can clear and release that connection concurrently, leaving the
network device registration path to dereference a freed parent device.
Take a reference to the L2CAP connection while holding the channel lock.
Retain it until register_netdev() has taken the parent device reference.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ebtables: terminate table name before find_table_lock()
update_counters() and compat_update_counters() forward a user-supplied
32-byte table name to find_table_lock() without NUL-terminating it. On a
lookup miss, find_inlist_lock() calls try_then_request_module(..., "%s%s",
"ebtable_", name), and vsnprintf() reads past the name field and the
stack object until it hits a zero byte.
BUG: KASAN: stack-out-of-bounds in string (lib/vsprintf.c:648 lib/vsprintf.c:730)
Read of size 1 at addr ffff8880119dfb20 by task exploit/147
Call Trace:
...
string (lib/vsprintf.c:648 lib/vsprintf.c:730)
vsnprintf (lib/vsprintf.c:2945)
__request_module (kernel/module/kmod.c:150)
do_update_counters.isra.0 (net/bridge/netfilter/ebtables.c:371 net/bridge/netfilter/ebtables.c:380)
update_counters (net/bridge/netfilter/ebtables.c:1440)
do_ebt_set_ctl (net/bridge/netfilter/ebtables.c:2573)
nf_setsockopt (net/netfilter/nf_sockopt.c:101)
ip_setsockopt (net/ipv4/ip_sockglue.c:1424)
raw_setsockopt (net/ipv4/raw.c:847)
__sys_setsockopt (net/socket.c:2393)
...
compat_do_replace() shares the same unterminated name via
compat_copy_ebt_replace_from_user(); terminate it there too so all
find_table_lock() callers behave alike. The other callers already
terminate the name after the copy.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ebtables: module names must be null-terminated
We need to explicitly check the length, else we may pass non-null
terminated string to request_module().
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: validate option length before reading conf opt value
l2cap_get_conf_opt() derives the option length from the
attacker-controlled opt->len field and immediately dereferences
opt->val (as u8, get_unaligned_le16() or get_unaligned_le32(), or a
raw pointer for the default case) before any caller has confirmed
that opt->len bytes are present in the buffer. The callers
(l2cap_parse_conf_req(), l2cap_parse_conf_rsp() and
l2cap_conf_rfc_get()) only detect a malformed option afterwards, once
the running length has gone negative, by which point the
out-of-bounds read has already executed.
An existing post-hoc length check keeps the garbage value from being
consumed, so this is not a data leak in the current control flow. It
is still a validate-after-use ordering bug: up to 4 bytes are read
past the end of the buffer before it is known to contain them, and it
is fragile to future changes in the callers.
Fix it at the source. Pass the end of the buffer into
l2cap_get_conf_opt() and refuse to touch opt->val unless the full
option (header + value) fits. Each caller computes an end pointer
once before the loop and checks the return value directly instead of
inferring the error from a negative length.
In the Linux kernel, the following vulnerability has been resolved:
smb/client: fix chown/chgrp with SMB3 POSIX Extensions
Ownership (chown) and group (chgrp) modifications were being ignored when
mounting with SMB3 POSIX Extensions unless CIFS_MOUNT_CIFS_ACL or
CIFS_MOUNT_MODE_FROM_SID were also explicitly set.
Fix this by checking for posix_extensions in cifs_setattr_nounix() when
updating UID and GID, ensuring that id_mode_to_cifs_acl() is called to map
and set the ownership/group information on the server.
In the Linux kernel, the following vulnerability has been resolved:
smb: client: mask server-provided mode to 07777 in modefromsid
When modefromsid is active, parse_dacl() applies the server-provided
sub_auth[2] value from the NFS mode SID to cf_mode without masking to
07777. Apply the correct masking, same as in the read path.
In the Linux kernel, the following vulnerability has been resolved:
smb: client: harden POSIX SID length parsing
posix_info_sid_size() reads sid[1] to obtain the subauthority count,
but its existing boundary check still accepts buffers with only one
remaining byte. Require two bytes before reading sid[1] so all client
paths that reuse the helper reject truncated POSIX SIDs safely.
In the Linux kernel, the following vulnerability has been resolved:
smb: client: Fix next buffer leak in receive_encrypted_standard()
receive_encrypted_standard() allocates next_buffer before checking
whether the number of compound PDUs already reached MAX_COMPOUND. If
the limit check fails, the function returns immediately and the newly
allocated next_buffer is not assigned to server->smallbuf/server->bigbuf,
making it leaked.
Move the MAX_COMPOUND check before allocating next_buffer.
In the Linux kernel, the following vulnerability has been resolved:
proc: protect ptrace_may_access() with exec_update_lock (part 1)
Fix the easy cases where procfs currently calls ptrace_may_access() without
exec_update_lock protection, where the fix is to simply add the extra lock
or use mm_access():
- do_task_stat(): grab exec_update_lock
- proc_pid_wchan(): grab exec_update_lock
- proc_map_files_lookup(): use mm_access() instead of get_task_mm()
- proc_map_files_readdir(): use mm_access() instead of get_task_mm()
- proc_ns_get_link(): grab exec_update_lock
- proc_ns_readlink(): grab exec_update_lock
In the Linux kernel, the following vulnerability has been resolved:
cpufreq: pcc: fix use-after-free and double free in _OSC evaluation
pcc_cpufreq_do_osc() calls acpi_evaluate_object() twice for the
two-phase _OSC negotiation. Between the two calls it freed
output.pointer but left output.length unchanged. Since
acpi_evaluate_object() treats a non-zero length with a non-NULL
pointer as an existing buffer to write into, the second call wrote
into freed memory (use-after-free). The subsequent kfree(output.pointer)
at out_free then freed the same pointer a second time (double free).
Reset output.pointer to NULL and output.length to ACPI_ALLOCATE_BUFFER
after freeing the first result, so ACPICA allocates a fresh buffer for
each phase independently.