Linux: >> Linux Kernel >> 3.18.52 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
ACPI: sysfs: validate return type of _STR method
Only buffer objects are valid return values of _STR.
If something else is returned description_show() will access invalid
memory.
CVSS Score
7.1
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix potential oob read in nilfs_btree_check_delete()
The function nilfs_btree_check_delete(), which checks whether degeneration
to direct mapping occurs before deleting a b-tree entry, causes memory
access outside the block buffer when retrieving the maximum key if the
root node has no entries.
This does not usually happen because b-tree mappings with 0 child nodes
are never created by mkfs.nilfs2 or nilfs2 itself. However, it can happen
if the b-tree root node read from a device is configured that way, so fix
this potential issue by adding a check for that case.
CVSS Score
7.1
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
f2fs: Require FMODE_WRITE for atomic write ioctls
The F2FS ioctls for starting and committing atomic writes check for
inode_owner_or_capable(), but this does not give LSMs like SELinux or
Landlock an opportunity to deny the write access - if the caller's FSUID
matches the inode's UID, inode_owner_or_capable() immediately returns true.
There are scenarios where LSMs want to deny a process the ability to write
particular files, even files that the FSUID of the process owns; but this
can currently partially be bypassed using atomic write ioctls in two ways:
- F2FS_IOC_START_ATOMIC_REPLACE + F2FS_IOC_COMMIT_ATOMIC_WRITE can
truncate an inode to size 0
- F2FS_IOC_START_ATOMIC_WRITE + F2FS_IOC_ABORT_ATOMIC_WRITE can revert
changes another process concurrently made to a file
Fix it by requiring FMODE_WRITE for these operations, just like for
F2FS_IOC_MOVE_RANGE. Since any legitimate caller should only be using these
ioctls when intending to write into the file, that seems unlikely to break
anything.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
firmware_loader: Block path traversal
Most firmware names are hardcoded strings, or are constructed from fairly
constrained format strings where the dynamic parts are just some hex
numbers or such.
However, there are a couple codepaths in the kernel where firmware file
names contain string components that are passed through from a device or
semi-privileged userspace; the ones I could find (not counting interfaces
that require root privileges) are:
- lpfc_sli4_request_firmware_update() seems to construct the firmware
filename from "ModelName", a string that was previously parsed out of
some descriptor ("Vital Product Data") in lpfc_fill_vpd()
- nfp_net_fw_find() seems to construct a firmware filename from a model
name coming from nfp_hwinfo_lookup(pf->hwinfo, "nffw.partno"), which I
think parses some descriptor that was read from the device.
(But this case likely isn't exploitable because the format string looks
like "netronome/nic_%s", and there shouldn't be any *folders* starting
with "netronome/nic_". The previous case was different because there,
the "%s" is *at the start* of the format string.)
- module_flash_fw_schedule() is reachable from the
ETHTOOL_MSG_MODULE_FW_FLASH_ACT netlink command, which is marked as
GENL_UNS_ADMIN_PERM (meaning CAP_NET_ADMIN inside a user namespace is
enough to pass the privilege check), and takes a userspace-provided
firmware name.
(But I think to reach this case, you need to have CAP_NET_ADMIN over a
network namespace that a special kind of ethernet device is mapped into,
so I think this is not a viable attack path in practice.)
Fix it by rejecting any firmware names containing ".." path components.
For what it's worth, I went looking and haven't found any USB device
drivers that use the firmware loader dangerously.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
mm: call the security_mmap_file() LSM hook in remap_file_pages()
The remap_file_pages syscall handler calls do_mmap() directly, which
doesn't contain the LSM security check. And if the process has called
personality(READ_IMPLIES_EXEC) before and remap_file_pages() is called for
RW pages, this will actually result in remapping the pages to RWX,
bypassing a W^X policy enforced by SELinux.
So we should check prot by security_mmap_file LSM hook in the
remap_file_pages syscall handler before do_mmap() is called. Otherwise, it
potentially permits an attacker to bypass a W^X policy enforced by
SELinux.
The bypass is similar to CVE-2016-10044, which bypass the same thing via
AIO and can be found in [1].
The PoC:
$ cat > test.c
int main(void) {
size_t pagesz = sysconf(_SC_PAGE_SIZE);
int mfd = syscall(SYS_memfd_create, "test", 0);
const char *buf = mmap(NULL, 4 * pagesz, PROT_READ | PROT_WRITE,
MAP_SHARED, mfd, 0);
unsigned int old = syscall(SYS_personality, 0xffffffff);
syscall(SYS_personality, READ_IMPLIES_EXEC | old);
syscall(SYS_remap_file_pages, buf, pagesz, 0, 2, 0);
syscall(SYS_personality, old);
// show the RWX page exists even if W^X policy is enforced
int fd = open("/proc/self/maps", O_RDONLY);
unsigned char buf2[1024];
while (1) {
int ret = read(fd, buf2, 1024);
if (ret <= 0) break;
write(1, buf2, ret);
}
close(fd);
}
$ gcc test.c -o test
$ ./test | grep rwx
7f1836c34000-7f1836c35000 rwxs 00002000 00:01 2050 /memfd:test (deleted)
[PM: subject line tweaks]
CVSS Score
7.8
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
RDMA/cxgb4: Added NULL check for lookup_atid
The lookup_atid() function can return NULL if the ATID is
invalid or does not exist in the identifier table, which
could lead to dereferencing a null pointer without a
check in the `act_establish()` and `act_open_rpl()` functions.
Add a NULL check to prevent null pointer dereferencing.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
nfsd: call cache_put if xdr_reserve_space returns NULL
If not enough buffer space available, but idmap_lookup has triggered
lookup_fn which calls cache_get and returns successfully. Then we
missed to call cache_put here which pairs with cache_get.
Reviwed-by: Jeff Layton <jlayton@kernel.org>
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
jfs: fix out-of-bounds in dbNextAG() and diAlloc()
In dbNextAG() , there is no check for the case where bmp->db_numag is
greater or same than MAXAG due to a polluted image, which causes an
out-of-bounds. Therefore, a bounds check should be added in dbMount().
And in dbNextAG(), a check for the case where agpref is greater than
bmp->db_numag should be added, so an out-of-bounds exception should be
prevented.
Additionally, a check for the case where agno is greater or same than
MAXAG should be added in diAlloc() to prevent out-of-bounds.
CVSS Score
7.1
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to wait dio completion
It should wait all existing dio write IOs before block removal,
otherwise, previous direct write IO may overwrite data in the
block which may be reused by other inode.
CVSS Score
6.5
EPSS Score
0.002
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: use two-phase skb reclamation in ieee80211_do_stop()
Since '__dev_queue_xmit()' should be called with interrupts enabled,
the following backtrace:
ieee80211_do_stop()
...
spin_lock_irqsave(&local->queue_stop_reason_lock, flags)
...
ieee80211_free_txskb()
ieee80211_report_used_skb()
ieee80211_report_ack_skb()
cfg80211_mgmt_tx_status_ext()
nl80211_frame_tx_status()
genlmsg_multicast_netns()
genlmsg_multicast_netns_filtered()
nlmsg_multicast_filtered()
netlink_broadcast_filtered()
do_one_broadcast()
netlink_broadcast_deliver()
__netlink_sendskb()
netlink_deliver_tap()
__netlink_deliver_tap_skb()
dev_queue_xmit()
__dev_queue_xmit() ; with IRQS disabled
...
spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags)
issues the warning (as reported by syzbot reproducer):
WARNING: CPU: 2 PID: 5128 at kernel/softirq.c:362 __local_bh_enable_ip+0xc3/0x120
Fix this by implementing a two-phase skb reclamation in
'ieee80211_do_stop()', where actual work is performed
outside of a section with interrupts disabled.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-21