In the Linux kernel, the following vulnerability has been resolved:
netfilter: ebtables: move to two-stage removal scheme
Like previous patches for x_tables, follow same pattern in ebtables.
We can't reuse xt helpers: ebt_table struct layout is incompatible.
table->ops assignment is now done while still holding the ebt mutex
to make sure we never expose partially-filled table struct.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: x_tables: add and use xtables_unregister_table_exit
Previous change added xtables_unregister_table_pre_exit to detach the
table from the packetpath and to unlink it from the active table list.
In case of rmmod, userspace that is doing set/getsockopt for this table
will not be able to re-instantiate the table:
1. The larval table has been removed already
2. existing instantiated table is no longer on the xt pernet table list.
This adds the second stage helper:
unlink the table from the dying list, free the hook ops (if any) and do
the audit notification. It replaces xt_unregister_table().
In the Linux kernel, the following vulnerability has been resolved:
netfilter: x_tables: allocate hook ops while under mutex
arp/ip(6)t_register_table() add the table to the per-netns list via
xt_register_table() before allocating the per-netns hook ops copy
via kmemdup_array(). This leaves a window where the table is
visible in the list with ops=NULL.
If the pernet exit happens runs concurrently the pre_exit callback finds
the table via xt_find_table() and passes the NULL ops pointer to
nf_unregister_net_hooks(), causing a NULL dereference:
general protection fault in nf_unregister_net_hooks+0xbc/0x150
RIP: nf_unregister_net_hooks (net/netfilter/core.c:613)
Call Trace:
ipt_unregister_table_pre_exit
iptable_mangle_net_pre_exit
ops_pre_exit_list
cleanup_net
Fix by moving the ops allocation into the xtables core so the table is
never in the list without valid ops. Also ensure the table is no longer
processing packets before its torn down on error unwind.
nf_register_net_hooks might have published at least one hook; call
synchronize_rcu() if there was an error.
audit log register message gets deferred until all operations have
passed, this avoids need to emit another ureg message in case of
error unwinding.
Based on earlier patch by Tristan Madani.
In the Linux kernel, the following vulnerability has been resolved:
crypto: nx - fix nx_crypto_ctx_exit argument
nx_crypto_ctx_shash_exit calls nx_crypto_ctx_exit with crypto_shash_ctx(...)
but crypto_shash_ctx gives a nx_crypto_ctx *, not a crypto_tfm *.
Fix the type in nx_crypto_ctx_exit and drop the bogus crypto_tfm_ctx
call.
This fixes the following oops:
BUG: Unable to handle kernel data access at 0xc0403effffffffc8
Faulting instruction address: 0xc000000000396cb4
Oops: Kernel access of bad area, sig: 11 [#15]
Call Trace:
nx_crypto_ctx_shash_exit+0x24/0x60
crypto_shash_exit_tfm+0x28/0x40
crypto_destroy_tfm+0x98/0x140
crypto_exit_ahash_using_shash+0x20/0x40
crypto_destroy_tfm+0x98/0x140
hash_release+0x1c/0x30
alg_sock_destruct+0x38/0x60
__sk_destruct+0x48/0x2b0
af_alg_release+0x58/0xb0
__sock_release+0x68/0x150
sock_close+0x20/0x40
__fput+0x110/0x3a0
sys_close+0x48/0xa0
system_call_exception+0x140/0x2d0
system_call_common+0xf4/0x258
.. which came from hardlink(1) opportunistically using AF_ALG.
The same problem exists with nx_crypto_ctx_skcipher_exit getting a context
it wasn't expecting, but apparently nobody hit that for years.
In the Linux kernel, the following vulnerability has been resolved:
fbdev: omap2: fix use-after-free in omapfb_mmap
omapfb_mmap() has a race condition with OMAPFB_SETUP_PLANE ioctl that
can lead to use-after-free:
The fb_mmap() entry point holds mm_lock but not lock (fb_info->lock),
while ioctl handlers like OMAPFB_SETUP_PLANE hold lock but not mm_lock.
This allows concurrent execution.
In omapfb_mmap():
1. rg = omapfb_get_mem_region(ofbi->region); // Get old region ref
2. start = omapfb_get_region_paddr(ofbi); // Read from NEW region
3. len = fix->smem_len; // Read from NEW region
4. vm_iomap_memory(vma, start, len); // Map NEW region memory
5. atomic_inc(&rg->map_count); // Increment OLD region!
Concurrently, OMAPFB_SETUP_PLANE can:
- Reassign ofbi->region = new_rg
- Update fix->smem_len
- OMAPFB_SETUP_MEM then checks NEW region's map_count (0!) and frees it
This leaves userspace with a mapping to freed physical memory.
The fix is to read all required values (start, len) from the same
region reference (rg) that will have its map_count incremented,
preventing the region from being freed while still mapped.
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: zero-initialize GART table on allocation
GART TLB is flushed after unmapping but not after mapping. Since
amdgpu_bo_create_kernel() does not zero-initialize the buffer, when a
single PTE is written the TLB may speculatively load other uninitialized
entries from the same cacheline. Those garbage entries can appear valid,
and a subsequent write to another PTE in the same cacheline may cause the
GPU to use a stale garbage PTE from the TLB.
Fix this by calling memset_io() to zero-initialize the GART table with
gart_pte_flags immediately after allocation.
Using AMDGPU_GEM_CREATE_VRAM_CLEARED, SDMA-based clear will not work
since SDMA needs GART to be initialized to work.
(cherry picked from commit d9af8263b82b6eaa60c5718e0c6631c5037e4b24)
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu/vce: Prevent partial address patches
In the case that only one of lo/hi is valid, the patching could result
in a bad address written to in FW.
In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: Add upper bound check for num_of_nodes
drm/amdkfd: Add upper bound check for num_of_nodes
in kfd_ioctl_get_process_apertures_new.
(cherry picked from commit 98ff46a5ea090c14d2cdb4f5b993b05d74f3949f)
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix fsck inconsistency caused by incorrect nat_entry flag usage
f2fs_need_dentry_mark() reads nat_entry flags without mutual exclusion
with the checkpoint path, which can result in an incorrect inode block
marking state. The scenario is as follows:
create & write & fsync 'file A' write checkpoint
- f2fs_do_sync_file // inline inode
- f2fs_write_inode // inode folio is dirty
- f2fs_write_checkpoint
- f2fs_flush_merged_writes
- f2fs_sync_node_pages
- f2fs_fsync_node_pages // no dirty node
- f2fs_need_inode_block_update // return true
- f2fs_fsync_node_pages // inode dirtied
- f2fs_need_dentry_mark //return true
- f2fs_flush_nat_entries
- f2fs_write_checkpoint end
- __write_node_folio // inode with DENT_BIT_SHIFT set
SPO, "fsck --dry-run" find inode has already checkpointed but still
with DENT_BIT_SHIFT set
The state observed by f2fs_need_dentry_mark() can differ from the state
observed in __write_node_folio() after acquiring sbi->node_write. The
root cause is that the semantics of IS_CHECKPOINTED and
HAS_FSYNCED_INODE are only guaranteed after the checkpoint write has
fully completed.
This patch moves set_dentry_mark() into __write_node_folio() and
protects it with the sbi->node_write lock.
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Fix shadow paging use-after-free due to unexpected role
Commit 0cb2af2ea66ad ("KVM: x86: Fix shadow paging use-after-free due
to unexpected GFN") fixed a shadow paging mismatch between stored and
computed GFNs; the bug could be triggered by changing a PDE mapping from
outside the guest, and then deleting a memslot. The rmap_remove()
call would miss entries created after the PDE change because the GFN
of the leaf SPTE does not match the GFN of the struct kvm_mmu_page.
A similar hole however remains if the modified PDE points to a non-leaf
page. In this case the gfn can be made to match, but the role does not
match: the original large 2MB page creates a kvm_mmu_page with direct=1,
while the new 4KB needs a kvm_mmu_page with direct=0. However,
kvm_mmu_get_child_sp() does not compare the role, and therefore reuses
the page.
The next step is installing a leaf (4KB) SPTE on the new path which
records an rmap entry under the gfn resolved by the walk. But when
that child is zapped its parent kvm_mmu_page has direct=1 and
kvm_mmu_page_get_gfn() computes the gfn for the 4KB page as
sp->gfn + index instead of using sp->shadowed_translation[] (or sp->gfns[]
in older kernels). It therefore fails to remove the recorded entry.
When the memslot is dropped the shadow page is freed but the rmap
entry survives, as in the scenario that was already fixed. Code that
later walks that gfn (dirty logging, MMU notifier invalidation, and
so on) dereferences an sptep that lies in the freed page, causing the
use-after-free.