Security Vulnerabilities
- CVEs Published In January 2025
In the Linux kernel, the following vulnerability has been resolved:
ipvs: fix UB due to uninitialized stack access in ip_vs_protocol_init()
Under certain kernel configurations when building with Clang/LLVM, the
compiler does not generate a return or jump as the terminator
instruction for ip_vs_protocol_init(), triggering the following objtool
warning during build time:
vmlinux.o: warning: objtool: ip_vs_protocol_init() falls through to next function __initstub__kmod_ip_vs_rr__935_123_ip_vs_rr_init6()
At runtime, this either causes an oops when trying to load the ipvs
module or a boot-time panic if ipvs is built-in. This same issue has
been reported by the Intel kernel test robot previously.
Digging deeper into both LLVM and the kernel code reveals this to be a
undefined behavior problem. ip_vs_protocol_init() uses a on-stack buffer
of 64 chars to store the registered protocol names and leaves it
uninitialized after definition. The function calls strnlen() when
concatenating protocol names into the buffer. With CONFIG_FORTIFY_SOURCE
strnlen() performs an extra step to check whether the last byte of the
input char buffer is a null character (commit 3009f891bb9f ("fortify:
Allow strlen() and strnlen() to pass compile-time known lengths")).
This, together with possibly other configurations, cause the following
IR to be generated:
define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #5 section ".init.text" align 16 !kcfi_type !29 {
%1 = alloca [64 x i8], align 16
...
14: ; preds = %11
%15 = getelementptr inbounds i8, ptr %1, i64 63
%16 = load i8, ptr %15, align 1
%17 = tail call i1 @llvm.is.constant.i8(i8 %16)
%18 = icmp eq i8 %16, 0
%19 = select i1 %17, i1 %18, i1 false
br i1 %19, label %20, label %23
20: ; preds = %14
%21 = call i64 @strlen(ptr noundef nonnull dereferenceable(1) %1) #23
...
23: ; preds = %14, %11, %20
%24 = call i64 @strnlen(ptr noundef nonnull dereferenceable(1) %1, i64 noundef 64) #24
...
}
The above code calculates the address of the last char in the buffer
(value %15) and then loads from it (value %16). Because the buffer is
never initialized, the LLVM GVN pass marks value %16 as undefined:
%13 = getelementptr inbounds i8, ptr %1, i64 63
br i1 undef, label %14, label %17
This gives later passes (SCCP, in particular) more DCE opportunities by
propagating the undef value further, and eventually removes everything
after the load on the uninitialized stack location:
define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #0 section ".init.text" align 16 !kcfi_type !11 {
%1 = alloca [64 x i8], align 16
...
12: ; preds = %11
%13 = getelementptr inbounds i8, ptr %1, i64 63
unreachable
}
In this way, the generated native code will just fall through to the
next function, as LLVM does not generate any code for the unreachable IR
instruction and leaves the function without a terminator.
Zero the on-stack buffer to avoid this possible UB.
In the Linux kernel, the following vulnerability has been resolved:
regulator: axp20x: AXP717: set ramp_delay
AXP717 datasheet says that regulator ramp delay is 15.625 us/step,
which is 10mV in our case.
Add a AXP_DESC_RANGES_DELAY macro and update AXP_DESC_RANGES macro to
expand to AXP_DESC_RANGES_DELAY with ramp_delay = 0
For DCDC4, steps is 100mv
Add a AXP_DESC_DELAY macro and update AXP_DESC macro to
expand to AXP_DESC_DELAY with ramp_delay = 0
This patch fix crashes when using CPU DVFS.
In the Linux kernel, the following vulnerability has been resolved:
ceph: give up on paths longer than PATH_MAX
If the full path to be built by ceph_mdsc_build_path() happens to be
longer than PATH_MAX, then this function will enter an endless (retry)
loop, effectively blocking the whole task. Most of the machine
becomes unusable, making this a very simple and effective DoS
vulnerability.
I cannot imagine why this retry was ever implemented, but it seems
rather useless and harmful to me. Let's remove it and fail with
ENAMETOOLONG instead.
In the Linux kernel, the following vulnerability has been resolved:
net/smc: check iparea_offset and ipv6_prefixes_cnt when receiving proposal msg
When receiving proposal msg in server, the field iparea_offset
and the field ipv6_prefixes_cnt in proposal msg are from the
remote client and can not be fully trusted. Especially the
field iparea_offset, once exceed the max value, there has the
chance to access wrong address, and crash may happen.
This patch checks iparea_offset and ipv6_prefixes_cnt before using them.
In the Linux kernel, the following vulnerability has been resolved:
sched/fair: Fix NEXT_BUDDY
Adam reports that enabling NEXT_BUDDY insta triggers a WARN in
pick_next_entity().
Moving clear_buddies() up before the delayed dequeue bits ensures
no ->next buddy becomes delayed. Further ensure no new ->next buddy
ever starts as delayed.
In the Linux kernel, the following vulnerability has been resolved:
spi: mpc52xx: Add cancel_work_sync before module remove
If we remove the module which will call mpc52xx_spi_remove
it will free 'ms' through spi_unregister_controller.
while the work ms->work will be used. The sequence of operations
that may lead to a UAF bug.
Fix it by ensuring that the work is canceled before proceeding with
the cleanup in mpc52xx_spi_remove.
In the Linux kernel, the following vulnerability has been resolved:
mm: use aligned address in copy_user_gigantic_page()
In current kernel, hugetlb_wp() calls copy_user_large_folio() with the
fault address. Where the fault address may be not aligned with the huge
page size. Then, copy_user_large_folio() may call
copy_user_gigantic_page() with the address, while
copy_user_gigantic_page() requires the address to be huge page size
aligned. So, this may cause memory corruption or information leak,
addtional, use more obvious naming 'addr_hint' instead of 'addr' for
copy_user_gigantic_page().
In the Linux kernel, the following vulnerability has been resolved:
mm: use aligned address in clear_gigantic_page()
In current kernel, hugetlb_no_page() calls folio_zero_user() with the
fault address. Where the fault address may be not aligned with the huge
page size. Then, folio_zero_user() may call clear_gigantic_page() with
the address, while clear_gigantic_page() requires the address to be huge
page size aligned. So, this may cause memory corruption or information
leak, addtional, use more obvious naming 'addr_hint' instead of 'addr' for
clear_gigantic_page().
In the Linux kernel, the following vulnerability has been resolved:
stackdepot: fix stack_depot_save_flags() in NMI context
Per documentation, stack_depot_save_flags() was meant to be usable from
NMI context if STACK_DEPOT_FLAG_CAN_ALLOC is unset. However, it still
would try to take the pool_lock in an attempt to save a stack trace in the
current pool (if space is available).
This could result in deadlock if an NMI is handled while pool_lock is
already held. To avoid deadlock, only try to take the lock in NMI context
and give up if unsuccessful.
The documentation is fixed to clearly convey this.
In the Linux kernel, the following vulnerability has been resolved:
bcache: revert replacing IS_ERR_OR_NULL with IS_ERR again
Commit 028ddcac477b ("bcache: Remove unnecessary NULL point check in
node allocations") leads a NULL pointer deference in cache_set_flush().
1721 if (!IS_ERR_OR_NULL(c->root))
1722 list_add(&c->root->list, &c->btree_cache);
>From the above code in cache_set_flush(), if previous registration code
fails before allocating c->root, it is possible c->root is NULL as what
it is initialized. __bch_btree_node_alloc() never returns NULL but
c->root is possible to be NULL at above line 1721.
This patch replaces IS_ERR() by IS_ERR_OR_NULL() to fix this.