Security Vulnerabilities - CVEs Published In February 2024
In the Linux kernel, the following vulnerability has been resolved:
ARM: 9064/1: hw_breakpoint: Do not directly check the event's overflow_handler hook
The commit 1879445dfa7b ("perf/core: Set event's default
::overflow_handler()") set a default event->overflow_handler in
perf_event_alloc(), and replace the check event->overflow_handler with
is_default_overflow_handler(), but one is missing.
Currently, the bp->overflow_handler can not be NULL. As a result,
enable_single_step() is always not invoked.
Comments from Zhen Lei:
https://patchwork.kernel.org/project/linux-arm-kernel/patch/20210207105934.2001-1-thunder.leizhen@huawei.com/
CVSS Score
5.5
EPSS Score
0.0
Published
2024-02-28
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix panic during f2fs_resize_fs()
f2fs_resize_fs() hangs in below callstack with testcase:
- mkfs 16GB image & mount image
- dd 8GB fileA
- dd 8GB fileB
- sync
- rm fileA
- sync
- resize filesystem to 8GB
kernel BUG at segment.c:2484!
Call Trace:
allocate_segment_by_default+0x92/0xf0 [f2fs]
f2fs_allocate_data_block+0x44b/0x7e0 [f2fs]
do_write_page+0x5a/0x110 [f2fs]
f2fs_outplace_write_data+0x55/0x100 [f2fs]
f2fs_do_write_data_page+0x392/0x850 [f2fs]
move_data_page+0x233/0x320 [f2fs]
do_garbage_collect+0x14d9/0x1660 [f2fs]
free_segment_range+0x1f7/0x310 [f2fs]
f2fs_resize_fs+0x118/0x330 [f2fs]
__f2fs_ioctl+0x487/0x3680 [f2fs]
__x64_sys_ioctl+0x8e/0xd0
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The root cause is we forgot to check that whether we have enough space
in resized filesystem to store all valid blocks in before-resizing
filesystem, then allocator will run out-of-space during block migration
in free_segment_range().
CVSS Score
5.5
EPSS Score
0.0
Published
2024-02-28
In the Linux kernel, the following vulnerability has been resolved:
KVM: SVM: Make sure GHCB is mapped before updating
Access to the GHCB is mainly in the VMGEXIT path and it is known that the
GHCB will be mapped. But there are two paths where it is possible the GHCB
might not be mapped.
The sev_vcpu_deliver_sipi_vector() routine will update the GHCB to inform
the caller of the AP Reset Hold NAE event that a SIPI has been delivered.
However, if a SIPI is performed without a corresponding AP Reset Hold,
then the GHCB might not be mapped (depending on the previous VMEXIT),
which will result in a NULL pointer dereference.
The svm_complete_emulated_msr() routine will update the GHCB to inform
the caller of a RDMSR/WRMSR operation about any errors. While it is likely
that the GHCB will be mapped in this situation, add a safe guard
in this path to be certain a NULL pointer dereference is not encountered.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-02-28
In the Linux kernel, the following vulnerability has been resolved:
KEYS: trusted: Fix memory leak on object td
Two error return paths are neglecting to free allocated object td,
causing a memory leak. Fix this by returning via the error return
path that securely kfree's td.
Fixes clang scan-build warning:
security/keys/trusted-keys/trusted_tpm1.c:496:10: warning: Potential
memory leak [unix.Malloc]
CVSS Score
5.5
EPSS Score
0.0
Published
2024-02-28
In the Linux kernel, the following vulnerability has been resolved:
net: Only allow init netns to set default tcp cong to a restricted algo
tcp_set_default_congestion_control() is netns-safe in that it writes
to &net->ipv4.tcp_congestion_control, but it also sets
ca->flags |= TCP_CONG_NON_RESTRICTED which is not namespaced.
This has the unintended side-effect of changing the global
net.ipv4.tcp_allowed_congestion_control sysctl, despite the fact that it
is read-only: 97684f0970f6 ("net: Make tcp_allowed_congestion_control
readonly in non-init netns")
Resolve this netns "leak" by only allowing the init netns to set the
default algorithm to one that is restricted. This restriction could be
removed if tcp_allowed_congestion_control were namespace-ified in the
future.
This bug was uncovered with
https://github.com/JonathonReinhart/linux-netns-sysctl-verify
CVSS Score
7.8
EPSS Score
0.0
Published
2024-02-28
In the Linux kernel, the following vulnerability has been resolved:
mm: memcontrol: slab: fix obtain a reference to a freeing memcg
Patch series "Use obj_cgroup APIs to charge kmem pages", v5.
Since Roman's series "The new cgroup slab memory controller" applied.
All slab objects are charged with the new APIs of obj_cgroup. The new
APIs introduce a struct obj_cgroup to charge slab objects. It prevents
long-living objects from pinning the original memory cgroup in the
memory. But there are still some corner objects (e.g. allocations
larger than order-1 page on SLUB) which are not charged with the new
APIs. Those objects (include the pages which are allocated from buddy
allocator directly) are charged as kmem pages which still hold a
reference to the memory cgroup.
E.g. We know that the kernel stack is charged as kmem pages because the
size of the kernel stack can be greater than 2 pages (e.g. 16KB on
x86_64 or arm64). If we create a thread (suppose the thread stack is
charged to memory cgroup A) and then move it from memory cgroup A to
memory cgroup B. Because the kernel stack of the thread hold a
reference to the memory cgroup A. The thread can pin the memory cgroup
A in the memory even if we remove the cgroup A. If we want to see this
scenario by using the following script. We can see that the system has
added 500 dying cgroups (This is not a real world issue, just a script
to show that the large kmallocs are charged as kmem pages which can pin
the memory cgroup in the memory).
#!/bin/bash
cat /proc/cgroups | grep memory
cd /sys/fs/cgroup/memory
echo 1 > memory.move_charge_at_immigrate
for i in range{1..500}
do
mkdir kmem_test
echo $$ > kmem_test/cgroup.procs
sleep 3600 &
echo $$ > cgroup.procs
echo `cat kmem_test/cgroup.procs` > cgroup.procs
rmdir kmem_test
done
cat /proc/cgroups | grep memory
This patchset aims to make those kmem pages to drop the reference to
memory cgroup by using the APIs of obj_cgroup. Finally, we can see that
the number of the dying cgroups will not increase if we run the above test
script.
This patch (of 7):
The rcu_read_lock/unlock only can guarantee that the memcg will not be
freed, but it cannot guarantee the success of css_get (which is in the
refill_stock when cached memcg changed) to memcg.
rcu_read_lock()
memcg = obj_cgroup_memcg(old)
__memcg_kmem_uncharge(memcg)
refill_stock(memcg)
if (stock->cached != memcg)
// css_get can change the ref counter from 0 back to 1.
css_get(&memcg->css)
rcu_read_unlock()
This fix is very like the commit:
eefbfa7fd678 ("mm: memcg/slab: fix use after free in obj_cgroup_charge")
Fix this by holding a reference to the memcg which is passed to the
__memcg_kmem_uncharge() before calling __memcg_kmem_uncharge().
CVSS Score
5.5
EPSS Score
0.0
Published
2024-02-28
In the Linux kernel, the following vulnerability has been resolved:
RDMA/siw: Fix a use after free in siw_alloc_mr
Our code analyzer reported a UAF.
In siw_alloc_mr(), it calls siw_mr_add_mem(mr,..). In the implementation of
siw_mr_add_mem(), mem is assigned to mr->mem and then mem is freed via
kfree(mem) if xa_alloc_cyclic() failed. Here, mr->mem still point to a
freed object. After, the execution continue up to the err_out branch of
siw_alloc_mr, and the freed mr->mem is used in siw_mr_drop_mem(mr).
My patch moves "mr->mem = mem" behind the if (xa_alloc_cyclic(..)<0) {}
section, to avoid the uaf.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-02-28
In the Linux kernel, the following vulnerability has been resolved:
net:emac/emac-mac: Fix a use after free in emac_mac_tx_buf_send
In emac_mac_tx_buf_send, it calls emac_tx_fill_tpd(..,skb,..).
If some error happens in emac_tx_fill_tpd(), the skb will be freed via
dev_kfree_skb(skb) in error branch of emac_tx_fill_tpd().
But the freed skb is still used via skb->len by netdev_sent_queue(,skb->len).
As i observed that emac_tx_fill_tpd() haven't modified the value of skb->len,
thus my patch assigns skb->len to 'len' before the possible free and
use 'len' instead of skb->len later.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-02-28
In the Linux kernel, the following vulnerability has been resolved:
net/sched: act_ct: fix wild memory access when clearing fragments
while testing re-assembly/re-fragmentation using act_ct, it's possible to
observe a crash like the following one:
KASAN: maybe wild-memory-access in range [0x0001000000000448-0x000100000000044f]
CPU: 50 PID: 0 Comm: swapper/50 Tainted: G S 5.12.0-rc7+ #424
Hardware name: Dell Inc. PowerEdge R730/072T6D, BIOS 2.4.3 01/17/2017
RIP: 0010:inet_frag_rbtree_purge+0x50/0xc0
Code: 00 fc ff df 48 89 c3 31 ed 48 89 df e8 a9 7a 38 ff 4c 89 fe 48 89 df 49 89 c6 e8 5b 3a 38 ff 48 8d 7b 40 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 75 59 48 8d bb d0 00 00 00 4c 8b 6b 40 48 89 f8 48
RSP: 0018:ffff888c31449db8 EFLAGS: 00010203
RAX: 0000200000000089 RBX: 000100000000040e RCX: ffffffff989eb960
RDX: 0000000000000140 RSI: ffffffff97cfb977 RDI: 000100000000044e
RBP: 0000000000000900 R08: 0000000000000000 R09: ffffed1186289350
R10: 0000000000000003 R11: ffffed1186289350 R12: dffffc0000000000
R13: 000100000000040e R14: 0000000000000000 R15: ffff888155e02160
FS: 0000000000000000(0000) GS:ffff888c31440000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005600cb70a5b8 CR3: 0000000a2c014005 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
inet_frag_destroy+0xa9/0x150
call_timer_fn+0x2d/0x180
run_timer_softirq+0x4fe/0xe70
__do_softirq+0x197/0x5a0
irq_exit_rcu+0x1de/0x200
sysvec_apic_timer_interrupt+0x6b/0x80
</IRQ>
when act_ct temporarily stores an IP fragment, restoring the skb qdisc cb
results in putting random data in FRAG_CB(), and this causes those "wild"
memory accesses later, when the rbtree is purged. Never overwrite the skb
cb in case tcf_ct_handle_fragments() returns -EINPROGRESS.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-02-28
In the Linux kernel, the following vulnerability has been resolved:
bnxt_en: Fix RX consumer index logic in the error path.
In bnxt_rx_pkt(), the RX buffers are expected to complete in order.
If the RX consumer index indicates an out of order buffer completion,
it means we are hitting a hardware bug and the driver will abort all
remaining RX packets and reset the RX ring. The RX consumer index
that we pass to bnxt_discard_rx() is not correct. We should be
passing the current index (tmp_raw_cons) instead of the old index
(raw_cons). This bug can cause us to be at the wrong index when
trying to abort the next RX packet. It can crash like this:
#0 [ffff9bbcdf5c39a8] machine_kexec at ffffffff9b05e007
#1 [ffff9bbcdf5c3a00] __crash_kexec at ffffffff9b111232
#2 [ffff9bbcdf5c3ad0] panic at ffffffff9b07d61e
#3 [ffff9bbcdf5c3b50] oops_end at ffffffff9b030978
#4 [ffff9bbcdf5c3b78] no_context at ffffffff9b06aaf0
#5 [ffff9bbcdf5c3bd8] __bad_area_nosemaphore at ffffffff9b06ae2e
#6 [ffff9bbcdf5c3c28] bad_area_nosemaphore at ffffffff9b06af24
#7 [ffff9bbcdf5c3c38] __do_page_fault at ffffffff9b06b67e
#8 [ffff9bbcdf5c3cb0] do_page_fault at ffffffff9b06bb12
#9 [ffff9bbcdf5c3ce0] page_fault at ffffffff9bc015c5
[exception RIP: bnxt_rx_pkt+237]
RIP: ffffffffc0259cdd RSP: ffff9bbcdf5c3d98 RFLAGS: 00010213
RAX: 000000005dd8097f RBX: ffff9ba4cb11b7e0 RCX: ffffa923cf6e9000
RDX: 0000000000000fff RSI: 0000000000000627 RDI: 0000000000001000
RBP: ffff9bbcdf5c3e60 R8: 0000000000420003 R9: 000000000000020d
R10: ffffa923cf6ec138 R11: ffff9bbcdf5c3e83 R12: ffff9ba4d6f928c0
R13: ffff9ba4cac28080 R14: ffff9ba4cb11b7f0 R15: ffff9ba4d5a30000
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
CVSS Score
5.5
EPSS Score
0.0
Published
2024-02-28