In the Linux kernel, the following vulnerability has been resolved:
cxl/port: Fix use-after-free, permit out-of-order decoder shutdown
In support of investigating an initialization failure report [1],
cxl_test was updated to register mock memory-devices after the mock
root-port/bus device had been registered. That led to cxl_test crashing
with a use-after-free bug with the following signature:
cxl_port_attach_region: cxl region3: cxl_host_bridge.0:port3 decoder3.0 add: mem0:decoder7.0 @ 0 next: cxl_switch_uport.0 nr_eps: 1 nr_targets: 1
cxl_port_attach_region: cxl region3: cxl_host_bridge.0:port3 decoder3.0 add: mem4:decoder14.0 @ 1 next: cxl_switch_uport.0 nr_eps: 2 nr_targets: 1
cxl_port_setup_targets: cxl region3: cxl_switch_uport.0:port6 target[0] = cxl_switch_dport.0 for mem0:decoder7.0 @ 0
1) cxl_port_setup_targets: cxl region3: cxl_switch_uport.0:port6 target[1] = cxl_switch_dport.4 for mem4:decoder14.0 @ 1
[..]
cxld_unregister: cxl decoder14.0:
cxl_region_decode_reset: cxl_region region3:
mock_decoder_reset: cxl_port port3: decoder3.0 reset
2) mock_decoder_reset: cxl_port port3: decoder3.0: out of order reset, expected decoder3.1
cxl_endpoint_decoder_release: cxl decoder14.0:
[..]
cxld_unregister: cxl decoder7.0:
3) cxl_region_decode_reset: cxl_region region3:
Oops: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6bc3: 0000 [#1] PREEMPT SMP PTI
[..]
RIP: 0010:to_cxl_port+0x8/0x60 [cxl_core]
[..]
Call Trace:
<TASK>
cxl_region_decode_reset+0x69/0x190 [cxl_core]
cxl_region_detach+0xe8/0x210 [cxl_core]
cxl_decoder_kill_region+0x27/0x40 [cxl_core]
cxld_unregister+0x5d/0x60 [cxl_core]
At 1) a region has been established with 2 endpoint decoders (7.0 and
14.0). Those endpoints share a common switch-decoder in the topology
(3.0). At teardown, 2), decoder14.0 is the first to be removed and hits
the "out of order reset case" in the switch decoder. The effect though
is that region3 cleanup is aborted leaving it in-tact and
referencing decoder14.0. At 3) the second attempt to teardown region3
trips over the stale decoder14.0 object which has long since been
deleted.
The fix here is to recognize that the CXL specification places no
mandate on in-order shutdown of switch-decoders, the driver enforces
in-order allocation, and hardware enforces in-order commit. So, rather
than fail and leave objects dangling, always remove them.
In support of making cxl_region_decode_reset() always succeed,
cxl_region_invalidate_memregion() failures are turned into warnings.
Crashing the kernel is ok there since system integrity is at risk if
caches cannot be managed around physical address mutation events like
CXL region destruction.
A new device_for_each_child_reverse_from() is added to cleanup
port->commit_end after all dependent decoders have been disabled. In
other words if decoders are allocated 0->1->2 and disabled 1->2->0 then
port->commit_end only decrements from 2 after 2 has been disabled, and
it decrements all the way to zero since 1 was disabled previously.
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix use-after-free of block device file in __btrfs_free_extra_devids()
Mounting btrfs from two images (which have the same one fsid and two
different dev_uuids) in certain executing order may trigger an UAF for
variable 'device->bdev_file' in __btrfs_free_extra_devids(). And
following are the details:
1. Attach image_1 to loop0, attach image_2 to loop1, and scan btrfs
devices by ioctl(BTRFS_IOC_SCAN_DEV):
/ btrfs_device_1 → loop0
fs_device
\ btrfs_device_2 → loop1
2. mount /dev/loop0 /mnt
btrfs_open_devices
btrfs_device_1->bdev_file = btrfs_get_bdev_and_sb(loop0)
btrfs_device_2->bdev_file = btrfs_get_bdev_and_sb(loop1)
btrfs_fill_super
open_ctree
fail: btrfs_close_devices // -ENOMEM
btrfs_close_bdev(btrfs_device_1)
fput(btrfs_device_1->bdev_file)
// btrfs_device_1->bdev_file is freed
btrfs_close_bdev(btrfs_device_2)
fput(btrfs_device_2->bdev_file)
3. mount /dev/loop1 /mnt
btrfs_open_devices
btrfs_get_bdev_and_sb(&bdev_file)
// EIO, btrfs_device_1->bdev_file is not assigned,
// which points to a freed memory area
btrfs_device_2->bdev_file = btrfs_get_bdev_and_sb(loop1)
btrfs_fill_super
open_ctree
btrfs_free_extra_devids
if (btrfs_device_1->bdev_file)
fput(btrfs_device_1->bdev_file) // UAF !
Fix it by setting 'device->bdev_file' as 'NULL' after closing the
btrfs_device in btrfs_close_one_device().
In the Linux kernel, the following vulnerability has been resolved:
udf: refactor inode_bmap() to handle error
Refactor inode_bmap() to handle error since udf_next_aext() can return
error now. On situations like ftruncate, udf_extend_file() can now
detect errors and bail out early without resorting to checking for
particular offsets and assuming internal behavior of these functions.
In the Linux kernel, the following vulnerability has been resolved:
cpufreq: loongson3: Use raw_smp_processor_id() in do_service_request()
Use raw_smp_processor_id() instead of plain smp_processor_id() in
do_service_request(), otherwise we may get some errors with the driver
enabled:
BUG: using smp_processor_id() in preemptible [00000000] code: (udev-worker)/208
caller is loongson3_cpufreq_probe+0x5c/0x250 [loongson3_cpufreq]
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix overloading of MEM_UNINIT's meaning
Lonial reported an issue in the BPF verifier where check_mem_size_reg()
has the following code:
if (!tnum_is_const(reg->var_off))
/* For unprivileged variable accesses, disable raw
* mode so that the program is required to
* initialize all the memory that the helper could
* just partially fill up.
*/
meta = NULL;
This means that writes are not checked when the register containing the
size of the passed buffer has not a fixed size. Through this bug, a BPF
program can write to a map which is marked as read-only, for example,
.rodata global maps.
The problem is that MEM_UNINIT's initial meaning that "the passed buffer
to the BPF helper does not need to be initialized" which was added back
in commit 435faee1aae9 ("bpf, verifier: add ARG_PTR_TO_RAW_STACK type")
got overloaded over time with "the passed buffer is being written to".
The problem however is that checks such as the above which were added later
via 06c1c049721a ("bpf: allow helpers access to variable memory") set meta
to NULL in order force the user to always initialize the passed buffer to
the helper. Due to the current double meaning of MEM_UNINIT, this bypasses
verifier write checks to the memory (not boundary checks though) and only
assumes the latter memory is read instead.
Fix this by reverting MEM_UNINIT back to its original meaning, and having
MEM_WRITE as an annotation to BPF helpers in order to then trigger the
BPF verifier checks for writing to memory.
Some notes: check_arg_pair_ok() ensures that for ARG_CONST_SIZE{,_OR_ZERO}
we can access fn->arg_type[arg - 1] since it must contain a preceding
ARG_PTR_TO_MEM. For check_mem_reg() the meta argument can be removed
altogether since we do check both BPF_READ and BPF_WRITE. Same for the
equivalent check_kfunc_mem_size_reg().
In the Linux kernel, the following vulnerability has been resolved:
fsl/fman: Fix refcount handling of fman-related devices
In mac_probe() there are multiple calls to of_find_device_by_node(),
fman_bind() and fman_port_bind() which takes references to of_dev->dev.
Not all references taken by these calls are released later on error path
in mac_probe() and in mac_remove() which lead to reference leaks.
Add references release.
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Don't call cleanup on profile rollback failure
When profile rollback fails in mlx5e_netdev_change_profile, the netdev
profile var is left set to NULL. Avoid a crash when unloading the driver
by not calling profile->cleanup in such a case.
This was encountered while testing, with the original trigger that
the wq rescuer thread creation got interrupted (presumably due to
Ctrl+C-ing modprobe), which gets converted to ENOMEM (-12) by
mlx5e_priv_init, the profile rollback also fails for the same reason
(signal still active) so the profile is left as NULL, leading to a crash
later in _mlx5e_remove.
[ 732.473932] mlx5_core 0000:08:00.1: E-Switch: Unload vfs: mode(OFFLOADS), nvfs(2), necvfs(0), active vports(2)
[ 734.525513] workqueue: Failed to create a rescuer kthread for wq "mlx5e": -EINTR
[ 734.557372] mlx5_core 0000:08:00.1: mlx5e_netdev_init_profile:6235:(pid 6086): mlx5e_priv_init failed, err=-12
[ 734.559187] mlx5_core 0000:08:00.1 eth3: mlx5e_netdev_change_profile: new profile init failed, -12
[ 734.560153] workqueue: Failed to create a rescuer kthread for wq "mlx5e": -EINTR
[ 734.589378] mlx5_core 0000:08:00.1: mlx5e_netdev_init_profile:6235:(pid 6086): mlx5e_priv_init failed, err=-12
[ 734.591136] mlx5_core 0000:08:00.1 eth3: mlx5e_netdev_change_profile: failed to rollback to orig profile, -12
[ 745.537492] BUG: kernel NULL pointer dereference, address: 0000000000000008
[ 745.538222] #PF: supervisor read access in kernel mode
<snipped>
[ 745.551290] Call Trace:
[ 745.551590] <TASK>
[ 745.551866] ? __die+0x20/0x60
[ 745.552218] ? page_fault_oops+0x150/0x400
[ 745.555307] ? exc_page_fault+0x79/0x240
[ 745.555729] ? asm_exc_page_fault+0x22/0x30
[ 745.556166] ? mlx5e_remove+0x6b/0xb0 [mlx5_core]
[ 745.556698] auxiliary_bus_remove+0x18/0x30
[ 745.557134] device_release_driver_internal+0x1df/0x240
[ 745.557654] bus_remove_device+0xd7/0x140
[ 745.558075] device_del+0x15b/0x3c0
[ 745.558456] mlx5_rescan_drivers_locked.part.0+0xb1/0x2f0 [mlx5_core]
[ 745.559112] mlx5_unregister_device+0x34/0x50 [mlx5_core]
[ 745.559686] mlx5_uninit_one+0x46/0xf0 [mlx5_core]
[ 745.560203] remove_one+0x4e/0xd0 [mlx5_core]
[ 745.560694] pci_device_remove+0x39/0xa0
[ 745.561112] device_release_driver_internal+0x1df/0x240
[ 745.561631] driver_detach+0x47/0x90
[ 745.562022] bus_remove_driver+0x84/0x100
[ 745.562444] pci_unregister_driver+0x3b/0x90
[ 745.562890] mlx5_cleanup+0xc/0x1b [mlx5_core]
[ 745.563415] __x64_sys_delete_module+0x14d/0x2f0
[ 745.563886] ? kmem_cache_free+0x1b0/0x460
[ 745.564313] ? lockdep_hardirqs_on_prepare+0xe2/0x190
[ 745.564825] do_syscall_64+0x6d/0x140
[ 745.565223] entry_SYSCALL_64_after_hwframe+0x4b/0x53
[ 745.565725] RIP: 0033:0x7f1579b1288b
In the Linux kernel, the following vulnerability has been resolved:
nvme-pci: fix race condition between reset and nvme_dev_disable()
nvme_dev_disable() modifies the dev->online_queues field, therefore
nvme_pci_update_nr_queues() should avoid racing against it, otherwise
we could end up passing invalid values to blk_mq_update_nr_hw_queues().
WARNING: CPU: 39 PID: 61303 at drivers/pci/msi/api.c:347
pci_irq_get_affinity+0x187/0x210
Workqueue: nvme-reset-wq nvme_reset_work [nvme]
RIP: 0010:pci_irq_get_affinity+0x187/0x210
Call Trace:
<TASK>
? blk_mq_pci_map_queues+0x87/0x3c0
? pci_irq_get_affinity+0x187/0x210
blk_mq_pci_map_queues+0x87/0x3c0
nvme_pci_map_queues+0x189/0x460 [nvme]
blk_mq_update_nr_hw_queues+0x2a/0x40
nvme_reset_work+0x1be/0x2a0 [nvme]
Fix the bug by locking the shutdown_lock mutex before using
dev->online_queues. Give up if nvme_dev_disable() is running or if
it has been executed already.