In the Linux kernel, the following vulnerability has been resolved:
nbd: fix uaf in nbd_genl_connect() error path
There is a use-after-free issue in nbd:
block nbd6: Receive control failed (result -104)
block nbd6: shutting down sockets
==================================================================
BUG: KASAN: slab-use-after-free in recv_work+0x694/0xa80 drivers/block/nbd.c:1022
Write of size 4 at addr ffff8880295de478 by task kworker/u33:0/67
CPU: 2 UID: 0 PID: 67 Comm: kworker/u33:0 Not tainted 6.15.0-rc5-syzkaller-00123-g2c89c1b655c0 #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: nbd6-recv recv_work
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0xc3/0x670 mm/kasan/report.c:521
kasan_report+0xe0/0x110 mm/kasan/report.c:634
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189
instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline]
recv_work+0x694/0xa80 drivers/block/nbd.c:1022
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
nbd_genl_connect() does not properly stop the device on certain
error paths after nbd_start_device() has been called. This causes
the error path to put nbd->config while recv_work continue to use
the config after putting it, leading to use-after-free in recv_work.
This patch moves nbd_start_device() after the backend file creation.
In the Linux kernel, the following vulnerability has been resolved:
raid10: cleanup memleak at raid10_make_request
If raid10_read_request or raid10_write_request registers a new
request and the REQ_NOWAIT flag is set, the code does not
free the malloc from the mempool.
unreferenced object 0xffff8884802c3200 (size 192):
comm "fio", pid 9197, jiffies 4298078271
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 88 41 02 00 00 00 00 00 .........A......
08 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc c1a049a2):
__kmalloc+0x2bb/0x450
mempool_alloc+0x11b/0x320
raid10_make_request+0x19e/0x650 [raid10]
md_handle_request+0x3b3/0x9e0
__submit_bio+0x394/0x560
__submit_bio_noacct+0x145/0x530
submit_bio_noacct_nocheck+0x682/0x830
__blkdev_direct_IO_async+0x4dc/0x6b0
blkdev_read_iter+0x1e5/0x3b0
__io_read+0x230/0x1110
io_read+0x13/0x30
io_issue_sqe+0x134/0x1180
io_submit_sqes+0x48c/0xe90
__do_sys_io_uring_enter+0x574/0x8b0
do_syscall_64+0x5c/0xe0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
V4: changing backing tree to see if CKI tests will pass.
The patch code has not changed between any versions.
In the Linux kernel, the following vulnerability has been resolved:
md/raid1: Fix stack memory use after return in raid1_reshape
In the raid1_reshape function, newpool is
allocated on the stack and assigned to conf->r1bio_pool.
This results in conf->r1bio_pool.wait.head pointing
to a stack address.
Accessing this address later can lead to a kernel panic.
Example access path:
raid1_reshape()
{
// newpool is on the stack
mempool_t newpool, oldpool;
// initialize newpool.wait.head to stack address
mempool_init(&newpool, ...);
conf->r1bio_pool = newpool;
}
raid1_read_request() or raid1_write_request()
{
alloc_r1bio()
{
mempool_alloc()
{
// if pool->alloc fails
remove_element()
{
--pool->curr_nr;
}
}
}
}
mempool_free()
{
if (pool->curr_nr < pool->min_nr) {
// pool->wait.head is a stack address
// wake_up() will try to access this invalid address
// which leads to a kernel panic
return;
wake_up(&pool->wait);
}
}
Fix:
reinit conf->r1bio_pool.wait after assigning newpool.
In the Linux kernel, the following vulnerability has been resolved:
drm/scheduler: signal scheduled fence when kill job
When an entity from application B is killed, drm_sched_entity_kill()
removes all jobs belonging to that entity through
drm_sched_entity_kill_jobs_work(). If application A's job depends on a
scheduled fence from application B's job, and that fence is not properly
signaled during the killing process, application A's dependency cannot be
cleared.
This leads to application A hanging indefinitely while waiting for a
dependency that will never be resolved. Fix this issue by ensuring that
scheduled fences are properly signaled when an entity is killed, allowing
dependent applications to continue execution.
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: Add basic validation for RAS header
If RAS header read from EEPROM is corrupted, it could result in trying
to allocate huge memory for reading the records. Add some validation to
header fields.
In the Linux kernel, the following vulnerability has been resolved:
bus: mhi: ep: Update read pointer only after buffer is written
Inside mhi_ep_ring_add_element, the read pointer (rd_offset) is updated
before the buffer is written, potentially causing race conditions where
the host sees an updated read pointer before the buffer is actually
written. Updating rd_offset prematurely can lead to the host accessing
an uninitialized or incomplete element, resulting in data corruption.
Invoke the buffer write before updating rd_offset to ensure the element
is fully written before signaling its availability.
In the Linux kernel, the following vulnerability has been resolved:
genirq/irq_sim: Initialize work context pointers properly
Initialize `ops` member's pointers properly by using kzalloc() instead of
kmalloc() when allocating the simulation work context. Otherwise the
pointers contain random content leading to invalid dereferencing.
In the Linux kernel, the following vulnerability has been resolved:
fs: export anon_inode_make_secure_inode() and fix secretmem LSM bypass
Export anon_inode_make_secure_inode() to allow KVM guest_memfd to create
anonymous inodes with proper security context. This replaces the current
pattern of calling alloc_anon_inode() followed by
inode_init_security_anon() for creating security context manually.
This change also fixes a security regression in secretmem where the
S_PRIVATE flag was not cleared after alloc_anon_inode(), causing
LSM/SELinux checks to be bypassed for secretmem file descriptors.
As guest_memfd currently resides in the KVM module, we need to export this
symbol for use outside the core kernel. In the future, guest_memfd might be
moved to core-mm, at which point the symbols no longer would have to be
exported. When/if that happens is still unclear.
In the Linux kernel, the following vulnerability has been resolved:
maple_tree: fix MA_STATE_PREALLOC flag in mas_preallocate()
Temporarily clear the preallocation flag when explicitly requesting
allocations. Pre-existing allocations are already counted against the
request through mas_node_count_gfp(), but the allocations will not happen
if the MA_STATE_PREALLOC flag is set. This flag is meant to avoid
re-allocating in bulk allocation mode, and to detect issues with
preallocation calculations.
The MA_STATE_PREALLOC flag should also always be set on zero allocations
so that detection of underflow allocations will print a WARN_ON() during
consumption.
User visible effect of this flaw is a WARN_ON() followed by a null pointer
dereference when subsequent requests for larger number of nodes is
ignored, such as the vma merge retry in mmap_region() caused by drivers
altering the vma flags (which happens in v6.6, at least)