CVE-2025-21692
7.8
HIGH
1 PoC
Analysis
EPSS 0.00
Linux kernel - Privilege Escalation
In the Linux kernel, the following vulnerability has been resolved:
net: sched: fix ets qdisc OOB Indexing
Haowei Yan <[email protected] > found that ets_class_from_arg() can
index an Out-Of-Bound class in ets_class_from_arg() when passed clid of
0. The overflow may cause local privilege escalation.
[ 18.852298] ------------[ cut here ]------------
[ 18.853271] UBSAN: array-index-out-of-bounds in net/sched/sch_ets.c:93:20
[ 18.853743] index 18446744073709551615 is out of range for type 'ets_class [16]'
[ 18.854254] CPU: 0 UID: 0 PID: 1275 Comm: poc Not tainted 6.12.6-dirty #17
[ 18.854821] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
[ 18.856532] Call Trace:
[ 18.857441] <TASK>
[ 18.858227] dump_stack_lvl+0xc2/0xf0
[ 18.859607] dump_stack+0x10/0x20
[ 18.860908] __ubsan_handle_out_of_bounds+0xa7/0xf0
[ 18.864022] ets_class_change+0x3d6/0x3f0
[ 18.864322] tc_ctl_tclass+0x251/0x910
[ 18.864587] ? lock_acquire+0x5e/0x140
[ 18.865113] ? __mutex_lock+0x9c/0xe70
[ 18.866009] ? __mutex_lock+0xa34/0xe70
[ 18.866401] rtnetlink_rcv_msg+0x170/0x6f0
[ 18.866806] ? __lock_acquire+0x578/0xc10
[ 18.867184] ? __pfx_rtnetlink_rcv_msg+0x10/0x10
[ 18.867503] netlink_rcv_skb+0x59/0x110
[ 18.867776] rtnetlink_rcv+0x15/0x30
[ 18.868159] netlink_unicast+0x1c3/0x2b0
[ 18.868440] netlink_sendmsg+0x239/0x4b0
[ 18.868721] ____sys_sendmsg+0x3e2/0x410
[ 18.869012] ___sys_sendmsg+0x88/0xe0
[ 18.869276] ? rseq_ip_fixup+0x198/0x260
[ 18.869563] ? rseq_update_cpu_node_id+0x10a/0x190
[ 18.869900] ? trace_hardirqs_off+0x5a/0xd0
[ 18.870196] ? syscall_exit_to_user_mode+0xcc/0x220
[ 18.870547] ? do_syscall_64+0x93/0x150
[ 18.870821] ? __memcg_slab_free_hook+0x69/0x290
[ 18.871157] __sys_sendmsg+0x69/0xd0
[ 18.871416] __x64_sys_sendmsg+0x1d/0x30
[ 18.871699] x64_sys_call+0x9e2/0x2670
[ 18.871979] do_syscall_64+0x87/0x150
[ 18.873280] ? do_syscall_64+0x93/0x150
[ 18.874742] ? lock_release+0x7b/0x160
[ 18.876157] ? do_user_addr_fault+0x5ce/0x8f0
[ 18.877833] ? irqentry_exit_to_user_mode+0xc2/0x210
[ 18.879608] ? irqentry_exit+0x77/0xb0
[ 18.879808] ? clear_bhb_loop+0x15/0x70
[ 18.880023] ? clear_bhb_loop+0x15/0x70
[ 18.880223] ? clear_bhb_loop+0x15/0x70
[ 18.880426] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 18.880683] RIP: 0033:0x44a957
[ 18.880851] Code: ff ff e8 fc 00 00 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 8974 24 10
[ 18.881766] RSP: 002b:00007ffcdd00fad8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 18.882149] RAX: ffffffffffffffda RBX: 00007ffcdd010db8 RCX: 000000000044a957
[ 18.882507] RDX: 0000000000000000 RSI: 00007ffcdd00fb70 RDI: 0000000000000003
[ 18.885037] RBP: 00007ffcdd010bc0 R08: 000000000703c770 R09: 000000000703c7c0
[ 18.887203] R10: 0000000000000080 R11: 0000000000000246 R12: 0000000000000001
[ 18.888026] R13: 00007ffcdd010da8 R14: 00000000004ca7d0 R15: 0000000000000001
[ 18.888395] </TASK>
[ 18.888610] ---[ end trace ]---
CWE-129
Feb 10, 2025
CVE-2024-50251
6.2
MEDIUM
1 PoC
Analysis
EPSS 0.00
Linux kernel - Buffer Overflow
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_payload: sanitize offset and length before calling skb_checksum()
If access to offset + length is larger than the skbuff length, then
skb_checksum() triggers BUG_ON().
skb_checksum() internally subtracts the length parameter while iterating
over skbuff, BUG_ON(len) at the end of it checks that the expected
length to be included in the checksum calculation is fully consumed.
Nov 09, 2024
CVE-2024-50164
7.1
HIGH
1 PoC
Analysis
EPSS 0.00
Linux kernel - Info Disclosure
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().
Nov 07, 2024
CVE-2024-50063
7.8
HIGH
1 PoC
Analysis
EPSS 0.00
Linux Kernel - RCE
In the Linux kernel, the following vulnerability has been resolved:
bpf: Prevent tail call between progs attached to different hooks
bpf progs can be attached to kernel functions, and the attached functions
can take different parameters or return different return values. If
prog attached to one kernel function tail calls prog attached to another
kernel function, the ctx access or return value verification could be
bypassed.
For example, if prog1 is attached to func1 which takes only 1 parameter
and prog2 is attached to func2 which takes two parameters. Since verifier
assumes the bpf ctx passed to prog2 is constructed based on func2's
prototype, verifier allows prog2 to access the second parameter from
the bpf ctx passed to it. The problem is that verifier does not prevent
prog1 from passing its bpf ctx to prog2 via tail call. In this case,
the bpf ctx passed to prog2 is constructed from func1 instead of func2,
that is, the assumption for ctx access verification is bypassed.
Another example, if BPF LSM prog1 is attached to hook file_alloc_security,
and BPF LSM prog2 is attached to hook bpf_lsm_audit_rule_known. Verifier
knows the return value rules for these two hooks, e.g. it is legal for
bpf_lsm_audit_rule_known to return positive number 1, and it is illegal
for file_alloc_security to return positive number. So verifier allows
prog2 to return positive number 1, but does not allow prog1 to return
positive number. The problem is that verifier does not prevent prog1
from calling prog2 via tail call. In this case, prog2's return value 1
will be used as the return value for prog1's hook file_alloc_security.
That is, the return value rule is bypassed.
This patch adds restriction for tail call to prevent such bypasses.
Oct 21, 2024
CVE-2024-49888
5.5
MEDIUM
1 PoC
Analysis
EPSS 0.00
Linux kernel - Memory Corruption
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix a sdiv overflow issue
Zac Ecob reported a problem where a bpf program may cause kernel crash due
to the following error:
Oops: divide error: 0000 [#1] PREEMPT SMP KASAN PTI
The failure is due to the below signed divide:
LLONG_MIN/-1 where LLONG_MIN equals to -9,223,372,036,854,775,808.
LLONG_MIN/-1 is supposed to give a positive number 9,223,372,036,854,775,808,
but it is impossible since for 64-bit system, the maximum positive
number is 9,223,372,036,854,775,807. On x86_64, LLONG_MIN/-1 will
cause a kernel exception. On arm64, the result for LLONG_MIN/-1 is
LLONG_MIN.
Further investigation found all the following sdiv/smod cases may trigger
an exception when bpf program is running on x86_64 platform:
- LLONG_MIN/-1 for 64bit operation
- INT_MIN/-1 for 32bit operation
- LLONG_MIN%-1 for 64bit operation
- INT_MIN%-1 for 32bit operation
where -1 can be an immediate or in a register.
On arm64, there are no exceptions:
- LLONG_MIN/-1 = LLONG_MIN
- INT_MIN/-1 = INT_MIN
- LLONG_MIN%-1 = 0
- INT_MIN%-1 = 0
where -1 can be an immediate or in a register.
Insn patching is needed to handle the above cases and the patched codes
produced results aligned with above arm64 result. The below are pseudo
codes to handle sdiv/smod exceptions including both divisor -1 and divisor 0
and the divisor is stored in a register.
sdiv:
tmp = rX
tmp += 1 /* [-1, 0] -> [0, 1]
if tmp >(unsigned) 1 goto L2
if tmp == 0 goto L1
rY = 0
L1:
rY = -rY;
goto L3
L2:
rY /= rX
L3:
smod:
tmp = rX
tmp += 1 /* [-1, 0] -> [0, 1]
if tmp >(unsigned) 1 goto L1
if tmp == 1 (is64 ? goto L2 : goto L3)
rY = 0;
goto L2
L1:
rY %= rX
L2:
goto L4 // only when !is64
L3:
wY = wY // only when !is64
L4:
[1] https://lore.kernel.org/bpf/tPJLTEh7S_DxFEqAI2Ji5MBSoZVg7_G-Py2iaZpAaWtM961fFTWtsnlzwvTbzBzaUzwQAoNATXKUlt0LZOFgnDcIyKCswAnAGdUF3LBrhGQ=@protonmail.com/
CWE-190
Oct 21, 2024
CVE-2024-49882
7.8
HIGH
1 PoC
Analysis
EPSS 0.00
Linux kernel - Info Disclosure
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix double brelse() the buffer of the extents path
In ext4_ext_try_to_merge_up(), set path[1].p_bh to NULL after it has been
released, otherwise it may be released twice. An example of what triggers
this is as follows:
split2 map split1
|--------|-------|--------|
ext4_ext_map_blocks
ext4_ext_handle_unwritten_extents
ext4_split_convert_extents
// path->p_depth == 0
ext4_split_extent
// 1. do split1
ext4_split_extent_at
|ext4_ext_insert_extent
| ext4_ext_create_new_leaf
| ext4_ext_grow_indepth
| le16_add_cpu(&neh->eh_depth, 1)
| ext4_find_extent
| // return -ENOMEM
|// get error and try zeroout
|path = ext4_find_extent
| path->p_depth = 1
|ext4_ext_try_to_merge
| ext4_ext_try_to_merge_up
| path->p_depth = 0
| brelse(path[1].p_bh) ---> not set to NULL here
|// zeroout success
// 2. update path
ext4_find_extent
// 3. do split2
ext4_split_extent_at
ext4_ext_insert_extent
ext4_ext_create_new_leaf
ext4_ext_grow_indepth
le16_add_cpu(&neh->eh_depth, 1)
ext4_find_extent
path[0].p_bh = NULL;
path->p_depth = 1
read_extent_tree_block ---> return err
// path[1].p_bh is still the old value
ext4_free_ext_path
ext4_ext_drop_refs
// path->p_depth == 1
brelse(path[1].p_bh) ---> brelse a buffer twice
Finally got the following WARRNING when removing the buffer from lru:
============================================
VFS: brelse: Trying to free free buffer
WARNING: CPU: 2 PID: 72 at fs/buffer.c:1241 __brelse+0x58/0x90
CPU: 2 PID: 72 Comm: kworker/u19:1 Not tainted 6.9.0-dirty #716
RIP: 0010:__brelse+0x58/0x90
Call Trace:
<TASK>
__find_get_block+0x6e7/0x810
bdev_getblk+0x2b/0x480
__ext4_get_inode_loc+0x48a/0x1240
ext4_get_inode_loc+0xb2/0x150
ext4_reserve_inode_write+0xb7/0x230
__ext4_mark_inode_dirty+0x144/0x6a0
ext4_ext_insert_extent+0x9c8/0x3230
ext4_ext_map_blocks+0xf45/0x2dc0
ext4_map_blocks+0x724/0x1700
ext4_do_writepages+0x12d6/0x2a70
[...]
============================================
CWE-415
Oct 21, 2024
CVE-2024-49861
7.1
HIGH
1 PoC
Analysis
EPSS 0.00
Linux kernel - Buffer Overflow
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix helper writes to read-only maps
Lonial found an issue that despite user- and BPF-side frozen BPF map
(like in case of .rodata), it was still possible to write into it from
a BPF program side through specific helpers having ARG_PTR_TO_{LONG,INT}
as arguments.
In check_func_arg() when the argument is as mentioned, the meta->raw_mode
is never set. Later, check_helper_mem_access(), under the case of
PTR_TO_MAP_VALUE as register base type, it assumes BPF_READ for the
subsequent call to check_map_access_type() and given the BPF map is
read-only it succeeds.
The helpers really need to be annotated as ARG_PTR_TO_{LONG,INT} | MEM_UNINIT
when results are written into them as opposed to read out of them. The
latter indicates that it's okay to pass a pointer to uninitialized memory
as the memory is written to anyway.
However, ARG_PTR_TO_{LONG,INT} is a special case of ARG_PTR_TO_FIXED_SIZE_MEM
just with additional alignment requirement. So it is better to just get
rid of the ARG_PTR_TO_{LONG,INT} special cases altogether and reuse the
fixed size memory types. For this, add MEM_ALIGNED to additionally ensure
alignment given these helpers write directly into the args via *<ptr> = val.
The .arg*_size has been initialized reflecting the actual sizeof(*<ptr>).
MEM_ALIGNED can only be used in combination with MEM_FIXED_SIZE annotated
argument types, since in !MEM_FIXED_SIZE cases the verifier does not know
the buffer size a priori and therefore cannot blindly write *<ptr> = val.
Oct 21, 2024
CVE-2024-47703
5.5
MEDIUM
1 PoC
Analysis
EPSS 0.00
Linux kernel - Use After Free
In the Linux kernel, the following vulnerability has been resolved:
bpf, lsm: Add check for BPF LSM return value
A bpf prog returning a positive number attached to file_alloc_security
hook makes kernel panic.
This happens because file system can not filter out the positive number
returned by the LSM prog using IS_ERR, and misinterprets this positive
number as a file pointer.
Given that hook file_alloc_security never returned positive number
before the introduction of BPF LSM, and other BPF LSM hooks may
encounter similar issues, this patch adds LSM return value check
in verifier, to ensure no unexpected value is returned.
Oct 21, 2024
CVE-2024-47702
5.5
MEDIUM
1 PoC
Analysis
EPSS 0.00
Linux kernel - Buffer Overflow
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fail verification for sign-extension of packet data/data_end/data_meta
syzbot reported a kernel crash due to
commit 1f1e864b6555 ("bpf: Handle sign-extenstin ctx member accesses").
The reason is due to sign-extension of 32-bit load for
packet data/data_end/data_meta uapi field.
The original code looks like:
r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */
r3 = *(u32 *)(r1 + 80) /* load __sk_buff->data_end */
r0 = r2
r0 += 8
if r3 > r0 goto +1
...
Note that __sk_buff->data load has 32-bit sign extension.
After verification and convert_ctx_accesses(), the final asm code looks like:
r2 = *(u64 *)(r1 +208)
r2 = (s32)r2
r3 = *(u64 *)(r1 +80)
r0 = r2
r0 += 8
if r3 > r0 goto pc+1
...
Note that 'r2 = (s32)r2' may make the kernel __sk_buff->data address invalid
which may cause runtime failure.
Currently, in C code, typically we have
void *data = (void *)(long)skb->data;
void *data_end = (void *)(long)skb->data_end;
...
and it will generate
r2 = *(u64 *)(r1 +208)
r3 = *(u64 *)(r1 +80)
r0 = r2
r0 += 8
if r3 > r0 goto pc+1
If we allow sign-extension,
void *data = (void *)(long)(int)skb->data;
void *data_end = (void *)(long)skb->data_end;
...
the generated code looks like
r2 = *(u64 *)(r1 +208)
r2 <<= 32
r2 s>>= 32
r3 = *(u64 *)(r1 +80)
r0 = r2
r0 += 8
if r3 > r0 goto pc+1
and this will cause verification failure since "r2 <<= 32" is not allowed
as "r2" is a packet pointer.
To fix this issue for case
r2 = *(s32 *)(r1 + 76) /* load __sk_buff->data */
this patch added additional checking in is_valid_access() callback
function for packet data/data_end/data_meta access. If those accesses
are with sign-extenstion, the verification will fail.
[1] https://lore.kernel.org/bpf/[email protected] /
Oct 21, 2024
CVE-2024-44947
5.5
MEDIUM
1 PoC
Analysis
EPSS 0.00
Linux kernel - Info Disclosure
In the Linux kernel, the following vulnerability has been resolved:
fuse: Initialize beyond-EOF page contents before setting uptodate
fuse_notify_store(), unlike fuse_do_readpage(), does not enable page
zeroing (because it can be used to change partial page contents).
So fuse_notify_store() must be more careful to fully initialize page
contents (including parts of the page that are beyond end-of-file)
before marking the page uptodate.
The current code can leave beyond-EOF page contents uninitialized, which
makes these uninitialized page contents visible to userspace via mmap().
This is an information leak, but only affects systems which do not
enable init-on-alloc (via CONFIG_INIT_ON_ALLOC_DEFAULT_ON=y or the
corresponding kernel command line parameter).
CWE-665
Sep 02, 2024
CVE-2024-44946
5.5
MEDIUM
1 PoC
Analysis
EPSS 0.00
Linux kernel - Use After Free
In the Linux kernel, the following vulnerability has been resolved:
kcm: Serialise kcm_sendmsg() for the same socket.
syzkaller reported UAF in kcm_release(). [0]
The scenario is
1. Thread A builds a skb with MSG_MORE and sets kcm->seq_skb.
2. Thread A resumes building skb from kcm->seq_skb but is blocked
by sk_stream_wait_memory()
3. Thread B calls sendmsg() concurrently, finishes building kcm->seq_skb
and puts the skb to the write queue
4. Thread A faces an error and finally frees skb that is already in the
write queue
5. kcm_release() does double-free the skb in the write queue
When a thread is building a MSG_MORE skb, another thread must not touch it.
Let's add a per-sk mutex and serialise kcm_sendmsg().
[0]:
BUG: KASAN: slab-use-after-free in __skb_unlink include/linux/skbuff.h:2366 [inline]
BUG: KASAN: slab-use-after-free in __skb_dequeue include/linux/skbuff.h:2385 [inline]
BUG: KASAN: slab-use-after-free in __skb_queue_purge_reason include/linux/skbuff.h:3175 [inline]
BUG: KASAN: slab-use-after-free in __skb_queue_purge include/linux/skbuff.h:3181 [inline]
BUG: KASAN: slab-use-after-free in kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691
Read of size 8 at addr ffff0000ced0fc80 by task syz-executor329/6167
CPU: 1 PID: 6167 Comm: syz-executor329 Tainted: G B 6.8.0-rc5-syzkaller-g9abbc24128bc #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call trace:
dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:291
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:298
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x178/0x518 mm/kasan/report.c:488
kasan_report+0xd8/0x138 mm/kasan/report.c:601
__asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381
__skb_unlink include/linux/skbuff.h:2366 [inline]
__skb_dequeue include/linux/skbuff.h:2385 [inline]
__skb_queue_purge_reason include/linux/skbuff.h:3175 [inline]
__skb_queue_purge include/linux/skbuff.h:3181 [inline]
kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691
__sock_release net/socket.c:659 [inline]
sock_close+0xa4/0x1e8 net/socket.c:1421
__fput+0x30c/0x738 fs/file_table.c:376
____fput+0x20/0x30 fs/file_table.c:404
task_work_run+0x230/0x2e0 kernel/task_work.c:180
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0x618/0x1f64 kernel/exit.c:871
do_group_exit+0x194/0x22c kernel/exit.c:1020
get_signal+0x1500/0x15ec kernel/signal.c:2893
do_signal+0x23c/0x3b44 arch/arm64/kernel/signal.c:1249
do_notify_resume+0x74/0x1f4 arch/arm64/kernel/entry-common.c:148
exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline]
exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline]
el0_svc+0xac/0x168 arch/arm64/kernel/entry-common.c:713
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598
Allocated by task 6166:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x40/0x78 mm/kasan/common.c:68
kasan_save_alloc_info+0x70/0x84 mm/kasan/generic.c:626
unpoison_slab_object mm/kasan/common.c:314 [inline]
__kasan_slab_alloc+0x74/0x8c mm/kasan/common.c:340
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slub.c:3813 [inline]
slab_alloc_node mm/slub.c:3860 [inline]
kmem_cache_alloc_node+0x204/0x4c0 mm/slub.c:3903
__alloc_skb+0x19c/0x3d8 net/core/skbuff.c:641
alloc_skb include/linux/skbuff.h:1296 [inline]
kcm_sendmsg+0x1d3c/0x2124 net/kcm/kcmsock.c:783
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
sock_sendmsg+0x220/0x2c0 net/socket.c:768
splice_to_socket+0x7cc/0xd58 fs/splice.c:889
do_splice_from fs/splice.c:941 [inline]
direct_splice_actor+0xec/0x1d8 fs/splice.c:1164
splice_direct_to_actor+0x438/0xa0c fs/splice.c:1108
do_splice_direct_actor
---truncated---
CWE-416
Aug 31, 2024
CVE-2024-36971
7.8
HIGH
KEV
1 PoC
Analysis
EPSS 0.01
Debian Linux < 4.19.316 - Use After Free
In the Linux kernel, the following vulnerability has been resolved:
net: fix __dst_negative_advice() race
__dst_negative_advice() does not enforce proper RCU rules when
sk->dst_cache must be cleared, leading to possible UAF.
RCU rules are that we must first clear sk->sk_dst_cache,
then call dst_release(old_dst).
Note that sk_dst_reset(sk) is implementing this protocol correctly,
while __dst_negative_advice() uses the wrong order.
Given that ip6_negative_advice() has special logic
against RTF_CACHE, this means each of the three ->negative_advice()
existing methods must perform the sk_dst_reset() themselves.
Note the check against NULL dst is centralized in
__dst_negative_advice(), there is no need to duplicate
it in various callbacks.
Many thanks to Clement Lecigne for tracking this issue.
This old bug became visible after the blamed commit, using UDP sockets.
CWE-416
Jun 10, 2024
CVE-2024-36886
7.8
HIGH
1 PoC
Analysis
EPSS 0.00
Linux kernel - Use After Free
In the Linux kernel, the following vulnerability has been resolved:
tipc: fix UAF in error path
Sam Page (sam4k) working with Trend Micro Zero Day Initiative reported
a UAF in the tipc_buf_append() error path:
BUG: KASAN: slab-use-after-free in kfree_skb_list_reason+0x47e/0x4c0
linux/net/core/skbuff.c:1183
Read of size 8 at addr ffff88804d2a7c80 by task poc/8034
CPU: 1 PID: 8034 Comm: poc Not tainted 6.8.2 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.0-debian-1.16.0-5 04/01/2014
Call Trace:
<IRQ>
__dump_stack linux/lib/dump_stack.c:88
dump_stack_lvl+0xd9/0x1b0 linux/lib/dump_stack.c:106
print_address_description linux/mm/kasan/report.c:377
print_report+0xc4/0x620 linux/mm/kasan/report.c:488
kasan_report+0xda/0x110 linux/mm/kasan/report.c:601
kfree_skb_list_reason+0x47e/0x4c0 linux/net/core/skbuff.c:1183
skb_release_data+0x5af/0x880 linux/net/core/skbuff.c:1026
skb_release_all linux/net/core/skbuff.c:1094
__kfree_skb linux/net/core/skbuff.c:1108
kfree_skb_reason+0x12d/0x210 linux/net/core/skbuff.c:1144
kfree_skb linux/./include/linux/skbuff.h:1244
tipc_buf_append+0x425/0xb50 linux/net/tipc/msg.c:186
tipc_link_input+0x224/0x7c0 linux/net/tipc/link.c:1324
tipc_link_rcv+0x76e/0x2d70 linux/net/tipc/link.c:1824
tipc_rcv+0x45f/0x10f0 linux/net/tipc/node.c:2159
tipc_udp_recv+0x73b/0x8f0 linux/net/tipc/udp_media.c:390
udp_queue_rcv_one_skb+0xad2/0x1850 linux/net/ipv4/udp.c:2108
udp_queue_rcv_skb+0x131/0xb00 linux/net/ipv4/udp.c:2186
udp_unicast_rcv_skb+0x165/0x3b0 linux/net/ipv4/udp.c:2346
__udp4_lib_rcv+0x2594/0x3400 linux/net/ipv4/udp.c:2422
ip_protocol_deliver_rcu+0x30c/0x4e0 linux/net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x2e4/0x520 linux/net/ipv4/ip_input.c:233
NF_HOOK linux/./include/linux/netfilter.h:314
NF_HOOK linux/./include/linux/netfilter.h:308
ip_local_deliver+0x18e/0x1f0 linux/net/ipv4/ip_input.c:254
dst_input linux/./include/net/dst.h:461
ip_rcv_finish linux/net/ipv4/ip_input.c:449
NF_HOOK linux/./include/linux/netfilter.h:314
NF_HOOK linux/./include/linux/netfilter.h:308
ip_rcv+0x2c5/0x5d0 linux/net/ipv4/ip_input.c:569
__netif_receive_skb_one_core+0x199/0x1e0 linux/net/core/dev.c:5534
__netif_receive_skb+0x1f/0x1c0 linux/net/core/dev.c:5648
process_backlog+0x101/0x6b0 linux/net/core/dev.c:5976
__napi_poll.constprop.0+0xba/0x550 linux/net/core/dev.c:6576
napi_poll linux/net/core/dev.c:6645
net_rx_action+0x95a/0xe90 linux/net/core/dev.c:6781
__do_softirq+0x21f/0x8e7 linux/kernel/softirq.c:553
do_softirq linux/kernel/softirq.c:454
do_softirq+0xb2/0xf0 linux/kernel/softirq.c:441
</IRQ>
<TASK>
__local_bh_enable_ip+0x100/0x120 linux/kernel/softirq.c:381
local_bh_enable linux/./include/linux/bottom_half.h:33
rcu_read_unlock_bh linux/./include/linux/rcupdate.h:851
__dev_queue_xmit+0x871/0x3ee0 linux/net/core/dev.c:4378
dev_queue_xmit linux/./include/linux/netdevice.h:3169
neigh_hh_output linux/./include/net/neighbour.h:526
neigh_output linux/./include/net/neighbour.h:540
ip_finish_output2+0x169f/0x2550 linux/net/ipv4/ip_output.c:235
__ip_finish_output linux/net/ipv4/ip_output.c:313
__ip_finish_output+0x49e/0x950 linux/net/ipv4/ip_output.c:295
ip_finish_output+0x31/0x310 linux/net/ipv4/ip_output.c:323
NF_HOOK_COND linux/./include/linux/netfilter.h:303
ip_output+0x13b/0x2a0 linux/net/ipv4/ip_output.c:433
dst_output linux/./include/net/dst.h:451
ip_local_out linux/net/ipv4/ip_output.c:129
ip_send_skb+0x3e5/0x560 linux/net/ipv4/ip_output.c:1492
udp_send_skb+0x73f/0x1530 linux/net/ipv4/udp.c:963
udp_sendmsg+0x1a36/0x2b40 linux/net/ipv4/udp.c:1250
inet_sendmsg+0x105/0x140 linux/net/ipv4/af_inet.c:850
sock_sendmsg_nosec linux/net/socket.c:730
__sock_sendmsg linux/net/socket.c:745
__sys_sendto+0x42c/0x4e0 linux/net/socket.c:2191
__do_sys_sendto linux/net/socket.c:2203
__se_sys_sendto linux/net/socket.c:2199
__x64_sys_sendto+0xe0/0x1c0 linux/net/socket.c:2199
do_syscall_x64 linux/arch/x86/entry/common.c:52
do_syscall_
---truncated---
CWE-416
May 30, 2024
CVE-2024-26589
7.8
HIGH
1 PoC
Analysis
EPSS 0.00
Linux Kernel < 5.15.148 - Memory Corruption
In the Linux kernel, the following vulnerability has been resolved:
bpf: Reject variable offset alu on PTR_TO_FLOW_KEYS
For PTR_TO_FLOW_KEYS, check_flow_keys_access() only uses fixed off
for validation. However, variable offset ptr alu is not prohibited
for this ptr kind. So the variable offset is not checked.
The following prog is accepted:
func#0 @0
0: R1=ctx() R10=fp0
0: (bf) r6 = r1 ; R1=ctx() R6_w=ctx()
1: (79) r7 = *(u64 *)(r6 +144) ; R6_w=ctx() R7_w=flow_keys()
2: (b7) r8 = 1024 ; R8_w=1024
3: (37) r8 /= 1 ; R8_w=scalar()
4: (57) r8 &= 1024 ; R8_w=scalar(smin=smin32=0,
smax=umax=smax32=umax32=1024,var_off=(0x0; 0x400))
5: (0f) r7 += r8
mark_precise: frame0: last_idx 5 first_idx 0 subseq_idx -1
mark_precise: frame0: regs=r8 stack= before 4: (57) r8 &= 1024
mark_precise: frame0: regs=r8 stack= before 3: (37) r8 /= 1
mark_precise: frame0: regs=r8 stack= before 2: (b7) r8 = 1024
6: R7_w=flow_keys(smin=smin32=0,smax=umax=smax32=umax32=1024,var_off
=(0x0; 0x400)) R8_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=1024,
var_off=(0x0; 0x400))
6: (79) r0 = *(u64 *)(r7 +0) ; R0_w=scalar()
7: (95) exit
This prog loads flow_keys to r7, and adds the variable offset r8
to r7, and finally causes out-of-bounds access:
BUG: unable to handle page fault for address: ffffc90014c80038
[...]
Call Trace:
<TASK>
bpf_dispatcher_nop_func include/linux/bpf.h:1231 [inline]
__bpf_prog_run include/linux/filter.h:651 [inline]
bpf_prog_run include/linux/filter.h:658 [inline]
bpf_prog_run_pin_on_cpu include/linux/filter.h:675 [inline]
bpf_flow_dissect+0x15f/0x350 net/core/flow_dissector.c:991
bpf_prog_test_run_flow_dissector+0x39d/0x620 net/bpf/test_run.c:1359
bpf_prog_test_run kernel/bpf/syscall.c:4107 [inline]
__sys_bpf+0xf8f/0x4560 kernel/bpf/syscall.c:5475
__do_sys_bpf kernel/bpf/syscall.c:5561 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5559 [inline]
__x64_sys_bpf+0x73/0xb0 kernel/bpf/syscall.c:5559
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
Fix this by rejecting ptr alu with variable offset on flow_keys.
Applying the patch rejects the program with "R7 pointer arithmetic
on flow_keys prohibited".
CWE-119
Feb 22, 2024