In the Linux kernel, the following vulnerability has been resolved:
net: rose: convert 'use' field to refcount_t
The 'use' field in struct rose_neigh is used as a reference counter but
lacks atomicity. This can lead to race conditions where a rose_neigh
structure is freed while still being referenced by other code paths.
For example, when rose_neigh->use becomes zero during an ioctl operation
via rose_rt_ioctl(), the structure may be removed while its timer is
still active, potentially causing use-after-free issues.
This patch changes the type of 'use' from unsigned short to refcount_t and
updates all code paths to use rose_neigh_hold() and rose_neigh_put() which
operate reference counts atomically.
In the Linux kernel, the following vulnerability has been resolved:
net: rose: include node references in rose_neigh refcount
Current implementation maintains two separate reference counting
mechanisms: the 'count' field in struct rose_neigh tracks references from
rose_node structures, while the 'use' field (now refcount_t) tracks
references from rose_sock.
This patch merges these two reference counting systems using 'use' field
for proper reference management. Specifically, this patch adds incrementing
and decrementing of rose_neigh->use when rose_neigh->count is incremented
or decremented.
This patch also modifies rose_rt_free(), rose_rt_device_down() and
rose_clear_route() to properly release references to rose_neigh objects
before freeing a rose_node through rose_remove_node().
These changes ensure rose_neigh structures are properly freed only when
all references, including those from rose_node structures, are released.
As a result, this resolves a slab-use-after-free issue reported by Syzbot.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: fix "bad unlock balance" in l2cap_disconnect_rsp
conn->chan_lock isn't acquired before l2cap_get_chan_by_scid,
if l2cap_get_chan_by_scid returns NULL, then 'bad unlock balance'
is triggered.
In the Linux kernel, the following vulnerability has been resolved:
blk-mq: fix NULL dereference on q->elevator in blk_mq_elv_switch_none
After grabbing q->sysfs_lock, q->elevator may become NULL because of
elevator switch.
Fix the NULL dereference on q->elevator by checking it with lock.
In the Linux kernel, the following vulnerability has been resolved:
udf: Do not update file length for failed writes to inline files
When write to inline file fails (or happens only partly), we still
updated length of inline data as if the whole write succeeded. Fix the
update of length of inline data to happen only if the write succeeds.
In the Linux kernel, the following vulnerability has been resolved:
scsi: lpfc: Fix use-after-free KFENCE violation during sysfs firmware write
During the sysfs firmware write process, a use-after-free read warning is
logged from the lpfc_wr_object() routine:
BUG: KFENCE: use-after-free read in lpfc_wr_object+0x235/0x310 [lpfc]
Use-after-free read at 0x0000000000cf164d (in kfence-#111):
lpfc_wr_object+0x235/0x310 [lpfc]
lpfc_write_firmware.cold+0x206/0x30d [lpfc]
lpfc_sli4_request_firmware_update+0xa6/0x100 [lpfc]
lpfc_request_firmware_upgrade_store+0x66/0xb0 [lpfc]
kernfs_fop_write_iter+0x121/0x1b0
new_sync_write+0x11c/0x1b0
vfs_write+0x1ef/0x280
ksys_write+0x5f/0xe0
do_syscall_64+0x59/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
The driver accessed wr_object pointer data, which was initialized into
mailbox payload memory, after the mailbox object was released back to the
mailbox pool.
Fix by moving the mailbox free calls to the end of the routine ensuring
that we don't reference internal mailbox memory after release.
In the Linux kernel, the following vulnerability has been resolved:
ext4: add bounds checking in get_max_inline_xattr_value_size()
Normally the extended attributes in the inode body would have been
checked when the inode is first opened, but if someone is writing to
the block device while the file system is mounted, it's possible for
the inode table to get corrupted. Add bounds checking to avoid
reading beyond the end of allocated memory if this happens.
In the Linux kernel, the following vulnerability has been resolved:
drm/client: Fix memory leak in drm_client_modeset_probe
When a new mode is set to modeset->mode, the previous mode should be freed.
This fixes the following kmemleak report:
drm_mode_duplicate+0x45/0x220 [drm]
drm_client_modeset_probe+0x944/0xf50 [drm]
__drm_fb_helper_initial_config_and_unlock+0xb4/0x2c0 [drm_kms_helper]
drm_fbdev_client_hotplug+0x2bc/0x4d0 [drm_kms_helper]
drm_client_register+0x169/0x240 [drm]
ast_pci_probe+0x142/0x190 [ast]
local_pci_probe+0xdc/0x180
work_for_cpu_fn+0x4e/0xa0
process_one_work+0x8b7/0x1540
worker_thread+0x70a/0xed0
kthread+0x29f/0x340
ret_from_fork+0x1f/0x30