| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Fix skb refcnt race after locking changes
There is a race where skb's from the sk_psock_backlog can be referenced
after userspace side has already skb_consumed() the sk_buff and its refcnt
dropped to zer0 causing use after free.
The flow is the following:
while ((skb = skb_peek(&psock->ingress_skb))
sk_psock_handle_Skb(psock, skb, ..., ingress)
if (!ingress) ...
sk_psock_skb_ingress
sk_psock_skb_ingress_enqueue(skb)
msg->skb = skb
sk_psock_queue_msg(psock, msg)
skb_dequeue(&psock->ingress_skb)
The sk_psock_queue_msg() puts the msg on the ingress_msg queue. This is
what the application reads when recvmsg() is called. An application can
read this anytime after the msg is placed on the queue. The recvmsg hook
will also read msg->skb and then after user space reads the msg will call
consume_skb(skb) on it effectively free'ing it.
But, the race is in above where backlog queue still has a reference to
the skb and calls skb_dequeue(). If the skb_dequeue happens after the
user reads and free's the skb we have a use after free.
The !ingress case does not suffer from this problem because it uses
sendmsg_*(sk, msg) which does not pass the sk_buff further down the
stack.
The following splat was observed with 'test_progs -t sockmap_listen':
[ 1022.710250][ T2556] general protection fault, ...
[...]
[ 1022.712830][ T2556] Workqueue: events sk_psock_backlog
[ 1022.713262][ T2556] RIP: 0010:skb_dequeue+0x4c/0x80
[ 1022.713653][ T2556] Code: ...
[...]
[ 1022.720699][ T2556] Call Trace:
[ 1022.720984][ T2556] <TASK>
[ 1022.721254][ T2556] ? die_addr+0x32/0x80^M
[ 1022.721589][ T2556] ? exc_general_protection+0x25a/0x4b0
[ 1022.722026][ T2556] ? asm_exc_general_protection+0x22/0x30
[ 1022.722489][ T2556] ? skb_dequeue+0x4c/0x80
[ 1022.722854][ T2556] sk_psock_backlog+0x27a/0x300
[ 1022.723243][ T2556] process_one_work+0x2a7/0x5b0
[ 1022.723633][ T2556] worker_thread+0x4f/0x3a0
[ 1022.723998][ T2556] ? __pfx_worker_thread+0x10/0x10
[ 1022.724386][ T2556] kthread+0xfd/0x130
[ 1022.724709][ T2556] ? __pfx_kthread+0x10/0x10
[ 1022.725066][ T2556] ret_from_fork+0x2d/0x50
[ 1022.725409][ T2556] ? __pfx_kthread+0x10/0x10
[ 1022.725799][ T2556] ret_from_fork_asm+0x1b/0x30
[ 1022.726201][ T2556] </TASK>
To fix we add an skb_get() before passing the skb to be enqueued in the
engress queue. This bumps the skb->users refcnt so that consume_skb()
and kfree_skb will not immediately free the sk_buff. With this we can
be sure the skb is still around when we do the dequeue. Then we just
need to decrement the refcnt or free the skb in the backlog case which
we do by calling kfree_skb() on the ingress case as well as the sendmsg
case.
Before locking change from fixes tag we had the sock locked so we
couldn't race with user and there was no issue here. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/vmwgfx: Fix memory leak in vmw_mksstat_add_ioctl()
If the copy of the description string from userspace fails, then the page
for the instance descriptor doesn't get freed before returning -EFAULT,
which leads to a memleak. |
| In the Linux kernel, the following vulnerability has been resolved:
seccomp: Move copy_seccomp() to no failure path.
Our syzbot instance reported memory leaks in do_seccomp() [0], similar
to the report [1]. It shows that we miss freeing struct seccomp_filter
and some objects included in it.
We can reproduce the issue with the program below [2] which calls one
seccomp() and two clone() syscalls.
The first clone()d child exits earlier than its parent and sends a
signal to kill it during the second clone(), more precisely before the
fatal_signal_pending() test in copy_process(). When the parent receives
the signal, it has to destroy the embryonic process and return -EINTR to
user space. In the failure path, we have to call seccomp_filter_release()
to decrement the filter's refcount.
Initially, we called it in free_task() called from the failure path, but
the commit 3a15fb6ed92c ("seccomp: release filter after task is fully
dead") moved it to release_task() to notify user space as early as possible
that the filter is no longer used.
To keep the change and current seccomp refcount semantics, let's move
copy_seccomp() just after the signal check and add a WARN_ON_ONCE() in
free_task() for future debugging.
[0]:
unreferenced object 0xffff8880063add00 (size 256):
comm "repro_seccomp", pid 230, jiffies 4294687090 (age 9.914s)
hex dump (first 32 bytes):
01 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 ................
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
backtrace:
do_seccomp (./include/linux/slab.h:600 ./include/linux/slab.h:733 kernel/seccomp.c:666 kernel/seccomp.c:708 kernel/seccomp.c:1871 kernel/seccomp.c:1991)
do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
unreferenced object 0xffffc90000035000 (size 4096):
comm "repro_seccomp", pid 230, jiffies 4294687090 (age 9.915s)
hex dump (first 32 bytes):
01 00 00 00 00 00 00 00 00 00 00 00 05 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
__vmalloc_node_range (mm/vmalloc.c:3226)
__vmalloc_node (mm/vmalloc.c:3261 (discriminator 4))
bpf_prog_alloc_no_stats (kernel/bpf/core.c:91)
bpf_prog_alloc (kernel/bpf/core.c:129)
bpf_prog_create_from_user (net/core/filter.c:1414)
do_seccomp (kernel/seccomp.c:671 kernel/seccomp.c:708 kernel/seccomp.c:1871 kernel/seccomp.c:1991)
do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
unreferenced object 0xffff888003fa1000 (size 1024):
comm "repro_seccomp", pid 230, jiffies 4294687090 (age 9.915s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
bpf_prog_alloc_no_stats (./include/linux/slab.h:600 ./include/linux/slab.h:733 kernel/bpf/core.c:95)
bpf_prog_alloc (kernel/bpf/core.c:129)
bpf_prog_create_from_user (net/core/filter.c:1414)
do_seccomp (kernel/seccomp.c:671 kernel/seccomp.c:708 kernel/seccomp.c:1871 kernel/seccomp.c:1991)
do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
unreferenced object 0xffff888006360240 (size 16):
comm "repro_seccomp", pid 230, jiffies 4294687090 (age 9.915s)
hex dump (first 16 bytes):
01 00 37 00 76 65 72 6c e0 83 01 06 80 88 ff ff ..7.verl........
backtrace:
bpf_prog_store_orig_filter (net/core/filter.c:1137)
bpf_prog_create_from_user (net/core/filter.c:1428)
do_seccomp (kernel/seccomp.c:671 kernel/seccomp.c:708 kernel/seccomp.c:1871 kernel/seccomp.c:1991)
do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
unreferenced object 0xffff888
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
drm/msm/dp: Drop aux devices together with DP controller
Using devres to depopulate the aux bus made sure that upon a probe
deferral the EDP panel device would be destroyed and recreated upon next
attempt.
But the struct device which the devres is tied to is the DPUs
(drm_dev->dev), which may be happen after the DP controller is torn
down.
Indications of this can be seen in the commonly seen EDID-hexdump full
of zeros in the log, or the occasional/rare KASAN fault where the
panel's attempt to read the EDID information causes a use after free on
DP resources.
It's tempting to move the devres to the DP controller's struct device,
but the resources used by the device(s) on the aux bus are explicitly
torn down in the error path. The KASAN-reported use-after-free also
remains, as the DP aux "module" explicitly frees its devres-allocated
memory in this code path.
As such, explicitly depopulate the aux bus in the error path, and in the
component unbind path, to avoid these issues.
Patchwork: https://patchwork.freedesktop.org/patch/542163/ |
| In the Linux kernel, the following vulnerability has been resolved:
md: fix warning for holder mismatch from export_rdev()
Commit a1d767191096 ("md: use mddev->external to select holder in
export_rdev()") fix the problem that 'claim_rdev' is used for
blkdev_get_by_dev() while 'rdev' is used for blkdev_put().
However, if mddev->external is changed from 0 to 1, then 'rdev' is used
for blkdev_get_by_dev() while 'claim_rdev' is used for blkdev_put(). And
this problem can be reporduced reliably by following:
New file: mdadm/tests/23rdev-lifetime
devname=${dev0##*/}
devt=`cat /sys/block/$devname/dev`
pid=""
runtime=2
clean_up_test() {
pill -9 $pid
echo clear > /sys/block/md0/md/array_state
}
trap 'clean_up_test' EXIT
add_by_sysfs() {
while true; do
echo $devt > /sys/block/md0/md/new_dev
done
}
remove_by_sysfs(){
while true; do
echo remove > /sys/block/md0/md/dev-${devname}/state
done
}
echo md0 > /sys/module/md_mod/parameters/new_array || die "create md0 failed"
add_by_sysfs &
pid="$pid $!"
remove_by_sysfs &
pid="$pid $!"
sleep $runtime
exit 0
Test cmd:
./test --save-logs --logdir=/tmp/ --keep-going --dev=loop --tests=23rdev-lifetime
Test result:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 960 at block/bdev.c:618 blkdev_put+0x27c/0x330
Modules linked in: multipath md_mod loop
CPU: 0 PID: 960 Comm: test Not tainted 6.5.0-rc2-00121-g01e55c376936-dirty #50
RIP: 0010:blkdev_put+0x27c/0x330
Call Trace:
<TASK>
export_rdev.isra.23+0x50/0xa0 [md_mod]
mddev_unlock+0x19d/0x300 [md_mod]
rdev_attr_store+0xec/0x190 [md_mod]
sysfs_kf_write+0x52/0x70
kernfs_fop_write_iter+0x19a/0x2a0
vfs_write+0x3b5/0x770
ksys_write+0x74/0x150
__x64_sys_write+0x22/0x30
do_syscall_64+0x40/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Fix the problem by recording if 'rdev' is used as holder. |
| In the Linux kernel, the following vulnerability has been resolved:
riscv: mm: add missing memcpy in kasan_init
Hi Atish,
It seems that the panic is due to the missing memcpy during kasan_init.
Could you please check whether this patch is helpful?
When doing kasan_populate, the new allocated base_pud/base_p4d should
contain kasan_early_shadow_{pud, p4d}'s content. Add the missing memcpy
to avoid page fault when read/write kasan shadow region.
Tested on:
- qemu with sv57 and CONFIG_KASAN on.
- qemu with sv48 and CONFIG_KASAN on. |
| In the Linux kernel, the following vulnerability has been resolved:
i40e: Fix DMA mappings leak
During reallocation of RX buffers, new DMA mappings are created for
those buffers.
steps for reproduction:
while :
do
for ((i=0; i<=8160; i=i+32))
do
ethtool -G enp130s0f0 rx $i tx $i
sleep 0.5
ethtool -g enp130s0f0
done
done
This resulted in crash:
i40e 0000:01:00.1: Unable to allocate memory for the Rx descriptor ring, size=65536
Driver BUG
WARNING: CPU: 0 PID: 4300 at net/core/xdp.c:141 xdp_rxq_info_unreg+0x43/0x50
Call Trace:
i40e_free_rx_resources+0x70/0x80 [i40e]
i40e_set_ringparam+0x27c/0x800 [i40e]
ethnl_set_rings+0x1b2/0x290
genl_family_rcv_msg_doit.isra.15+0x10f/0x150
genl_family_rcv_msg+0xb3/0x160
? rings_fill_reply+0x1a0/0x1a0
genl_rcv_msg+0x47/0x90
? genl_family_rcv_msg+0x160/0x160
netlink_rcv_skb+0x4c/0x120
genl_rcv+0x24/0x40
netlink_unicast+0x196/0x230
netlink_sendmsg+0x204/0x3d0
sock_sendmsg+0x4c/0x50
__sys_sendto+0xee/0x160
? handle_mm_fault+0xbe/0x1e0
? syscall_trace_enter+0x1d3/0x2c0
__x64_sys_sendto+0x24/0x30
do_syscall_64+0x5b/0x1a0
entry_SYSCALL_64_after_hwframe+0x65/0xca
RIP: 0033:0x7f5eac8b035b
Missing register, driver bug
WARNING: CPU: 0 PID: 4300 at net/core/xdp.c:119 xdp_rxq_info_unreg_mem_model+0x69/0x140
Call Trace:
xdp_rxq_info_unreg+0x1e/0x50
i40e_free_rx_resources+0x70/0x80 [i40e]
i40e_set_ringparam+0x27c/0x800 [i40e]
ethnl_set_rings+0x1b2/0x290
genl_family_rcv_msg_doit.isra.15+0x10f/0x150
genl_family_rcv_msg+0xb3/0x160
? rings_fill_reply+0x1a0/0x1a0
genl_rcv_msg+0x47/0x90
? genl_family_rcv_msg+0x160/0x160
netlink_rcv_skb+0x4c/0x120
genl_rcv+0x24/0x40
netlink_unicast+0x196/0x230
netlink_sendmsg+0x204/0x3d0
sock_sendmsg+0x4c/0x50
__sys_sendto+0xee/0x160
? handle_mm_fault+0xbe/0x1e0
? syscall_trace_enter+0x1d3/0x2c0
__x64_sys_sendto+0x24/0x30
do_syscall_64+0x5b/0x1a0
entry_SYSCALL_64_after_hwframe+0x65/0xca
RIP: 0033:0x7f5eac8b035b
This was caused because of new buffers with different RX ring count should
substitute older ones, but those buffers were freed in
i40e_configure_rx_ring and reallocated again with i40e_alloc_rx_bi,
thus kfree on rx_bi caused leak of already mapped DMA.
Fix this by reallocating ZC with rx_bi_zc struct when BPF program loads. Additionally
reallocate back to rx_bi when BPF program unloads.
If BPF program is loaded/unloaded and XSK pools are created, reallocate
RX queues accordingly in XSP_SETUP_XSK_POOL handler. |
| In the Linux kernel, the following vulnerability has been resolved:
cpufreq: qcom: fix memory leak in error path
If for some reason the speedbin length is incorrect, then there is a
memory leak in the error path because we never free the speedbin buffer.
This commit fixes the error path to always free the speedbin buffer. |
| In the Linux kernel, the following vulnerability has been resolved:
hwrng: geode - Fix PCI device refcount leak
for_each_pci_dev() is implemented by pci_get_device(). The comment of
pci_get_device() says that it will increase the reference count for the
returned pci_dev and also decrease the reference count for the input
pci_dev @from if it is not NULL.
If we break for_each_pci_dev() loop with pdev not NULL, we need to call
pci_dev_put() to decrease the reference count. We add a new struct
'amd_geode_priv' to record pointer of the pci_dev and membase, and then
add missing pci_dev_put() for the normal and error path. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/rxe: Fix "kernel NULL pointer dereference" error
When rxe_queue_init in the function rxe_qp_init_req fails,
both qp->req.task.func and qp->req.task.arg are not initialized.
Because of creation of qp fails, the function rxe_create_qp will
call rxe_qp_do_cleanup to handle allocated resource.
Before calling __rxe_do_task, both qp->req.task.func and
qp->req.task.arg should be checked. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: ath11k: fix failed to find the peer with peer_id 0 when disconnected
It has a fail log which is ath11k_dbg in ath11k_dp_rx_process_mon_status(),
as below, it will not print when debug_mask is not set ATH11K_DBG_DATA.
ath11k_dbg(ab, ATH11K_DBG_DATA,
"failed to find the peer with peer_id %d\n",
ppdu_info.peer_id);
When run scan with station disconnected, the peer_id is 0 for case
HAL_RX_MPDU_START in ath11k_hal_rx_parse_mon_status_tlv() which called
from ath11k_dp_rx_process_mon_status(), and the peer_id of ppdu_info is
reset to 0 in the while loop, so it does not match condition of the
check "if (ppdu_info->peer_id == HAL_INVALID_PEERID" in the loop, and
then the log "failed to find the peer with peer_id 0" print after the
check in the loop, it is below call stack when debug_mask is set
ATH11K_DBG_DATA.
The reason is this commit 01d2f285e3e5 ("ath11k: decode HE status tlv")
add "memset(ppdu_info, 0, sizeof(struct hal_rx_mon_ppdu_info))" in
ath11k_dp_rx_process_mon_status(), but the commit does not initialize
the peer_id to HAL_INVALID_PEERID, then lead the check mis-match.
Callstack of the failed log:
[12335.689072] RIP: 0010:ath11k_dp_rx_process_mon_status+0x9ea/0x1020 [ath11k]
[12335.689157] Code: 89 ff e8 f9 10 00 00 be 01 00 00 00 4c 89 f7 e8 dc 4b 4e de 48 8b 85 38 ff ff ff c7 80 e4 07 00 00 01 00 00 00 e9 20 f8 ff ff <0f> 0b 41 0f b7 96 be 06 00 00 48 c7 c6 b8 50 44 c1 4c 89 ff e8 fd
[12335.689180] RSP: 0018:ffffb874001a4ca0 EFLAGS: 00010246
[12335.689210] RAX: 0000000000000000 RBX: ffff995642cbd100 RCX: 0000000000000000
[12335.689229] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff99564212cd18
[12335.689248] RBP: ffffb874001a4dc0 R08: 0000000000000001 R09: 0000000000000000
[12335.689268] R10: 0000000000000220 R11: ffffb874001a48e8 R12: ffff995642473d40
[12335.689286] R13: ffff99564212c5b8 R14: ffff9956424736a0 R15: ffff995642120000
[12335.689303] FS: 0000000000000000(0000) GS:ffff995739000000(0000) knlGS:0000000000000000
[12335.689323] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[12335.689341] CR2: 00007f43c5d5e039 CR3: 000000011c012005 CR4: 00000000000606e0
[12335.689360] Call Trace:
[12335.689377] <IRQ>
[12335.689418] ? rcu_read_lock_held_common+0x12/0x50
[12335.689447] ? rcu_read_lock_sched_held+0x25/0x80
[12335.689471] ? rcu_read_lock_held_common+0x12/0x50
[12335.689504] ath11k_dp_rx_process_mon_rings+0x8d/0x4f0 [ath11k]
[12335.689578] ? ath11k_dp_rx_process_mon_rings+0x8d/0x4f0 [ath11k]
[12335.689653] ? lock_acquire+0xef/0x360
[12335.689681] ? rcu_read_lock_sched_held+0x25/0x80
[12335.689713] ath11k_dp_service_mon_ring+0x38/0x60 [ath11k]
[12335.689784] ? ath11k_dp_rx_process_mon_rings+0x4f0/0x4f0 [ath11k]
[12335.689860] call_timer_fn+0xb2/0x2f0
[12335.689897] ? ath11k_dp_rx_process_mon_rings+0x4f0/0x4f0 [ath11k]
[12335.689970] run_timer_softirq+0x21f/0x540
[12335.689999] ? ktime_get+0xad/0x160
[12335.690025] ? lapic_next_deadline+0x2c/0x40
[12335.690053] ? clockevents_program_event+0x82/0x100
[12335.690093] __do_softirq+0x151/0x4a8
[12335.690135] irq_exit_rcu+0xc9/0x100
[12335.690165] sysvec_apic_timer_interrupt+0xa8/0xd0
[12335.690189] </IRQ>
[12335.690204] <TASK>
[12335.690225] asm_sysvec_apic_timer_interrupt+0x12/0x20
Reset the default value to HAL_INVALID_PEERID each time after memset
of ppdu_info as well as others memset which existed in function
ath11k_dp_rx_process_mon_status(), then the failed log disappeared.
Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3 |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: ipw2200: fix memory leak in ipw_wdev_init()
In the error path of ipw_wdev_init(), exception value is returned, and
the memory applied for in the function is not released. Also the memory
is not released in ipw_pci_probe(). As a result, memory leakage occurs.
So memory release needs to be added to the error path of ipw_wdev_init(). |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix panic due to wrong pageattr of im->image
In the scenario where livepatch and kretfunc coexist, the pageattr of
im->image is rox after arch_prepare_bpf_trampoline in
bpf_trampoline_update, and then modify_fentry or register_fentry returns
-EAGAIN from bpf_tramp_ftrace_ops_func, the BPF_TRAMP_F_ORIG_STACK flag
will be configured, and arch_prepare_bpf_trampoline will be re-executed.
At this time, because the pageattr of im->image is rox,
arch_prepare_bpf_trampoline will read and write im->image, which causes
a fault. as follows:
insmod livepatch-sample.ko # samples/livepatch/livepatch-sample.c
bpftrace -e 'kretfunc:cmdline_proc_show {}'
BUG: unable to handle page fault for address: ffffffffa0206000
PGD 322d067 P4D 322d067 PUD 322e063 PMD 1297e067 PTE d428061
Oops: 0003 [#1] PREEMPT SMP PTI
CPU: 2 PID: 270 Comm: bpftrace Tainted: G E K 6.1.0 #5
RIP: 0010:arch_prepare_bpf_trampoline+0xed/0x8c0
RSP: 0018:ffffc90001083ad8 EFLAGS: 00010202
RAX: ffffffffa0206000 RBX: 0000000000000020 RCX: 0000000000000000
RDX: ffffffffa0206001 RSI: ffffffffa0206000 RDI: 0000000000000030
RBP: ffffc90001083b70 R08: 0000000000000066 R09: ffff88800f51b400
R10: 000000002e72c6e5 R11: 00000000d0a15080 R12: ffff8880110a68c8
R13: 0000000000000000 R14: ffff88800f51b400 R15: ffffffff814fec10
FS: 00007f87bc0dc780(0000) GS:ffff88803e600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffa0206000 CR3: 0000000010b70000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
bpf_trampoline_update+0x25a/0x6b0
__bpf_trampoline_link_prog+0x101/0x240
bpf_trampoline_link_prog+0x2d/0x50
bpf_tracing_prog_attach+0x24c/0x530
bpf_raw_tp_link_attach+0x73/0x1d0
__sys_bpf+0x100e/0x2570
__x64_sys_bpf+0x1c/0x30
do_syscall_64+0x5b/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
With this patch, when modify_fentry or register_fentry returns -EAGAIN
from bpf_tramp_ftrace_ops_func, the pageattr of im->image will be reset
to nx+rw. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix reference state management for synchronous callbacks
Currently, verifier verifies callback functions (sync and async) as if
they will be executed once, (i.e. it explores execution state as if the
function was being called once). The next insn to explore is set to
start of subprog and the exit from nested frame is handled using
curframe > 0 and prepare_func_exit. In case of async callback it uses a
customized variant of push_stack simulating a kind of branch to set up
custom state and execution context for the async callback.
While this approach is simple and works when callback really will be
executed only once, it is unsafe for all of our current helpers which
are for_each style, i.e. they execute the callback multiple times.
A callback releasing acquired references of the caller may do so
multiple times, but currently verifier sees it as one call inside the
frame, which then returns to caller. Hence, it thinks it released some
reference that the cb e.g. got access through callback_ctx (register
filled inside cb from spilled typed register on stack).
Similarly, it may see that an acquire call is unpaired inside the
callback, so the caller will copy the reference state of callback and
then will have to release the register with new ref_obj_ids. But again,
the callback may execute multiple times, but the verifier will only
account for acquired references for a single symbolic execution of the
callback, which will cause leaks.
Note that for async callback case, things are different. While currently
we have bpf_timer_set_callback which only executes it once, even for
multiple executions it would be safe, as reference state is NULL and
check_reference_leak would force program to release state before
BPF_EXIT. The state is also unaffected by analysis for the caller frame.
Hence async callback is safe.
Since we want the reference state to be accessible, e.g. for pointers
loaded from stack through callback_ctx's PTR_TO_STACK, we still have to
copy caller's reference_state to callback's bpf_func_state, but we
enforce that whatever references it adds to that reference_state has
been released before it hits BPF_EXIT. This requires introducing a new
callback_ref member in the reference state to distinguish between caller
vs callee references. Hence, check_reference_leak now errors out if it
sees we are in callback_fn and we have not released callback_ref refs.
Since there can be multiple nested callbacks, like frame 0 -> cb1 -> cb2
etc. we need to also distinguish between whether this particular ref
belongs to this callback frame or parent, and only error for our own, so
we store state->frameno (which is always non-zero for callbacks).
In short, callbacks can read parent reference_state, but cannot mutate
it, to be able to use pointers acquired by the caller. They must only
undo their changes (by releasing their own acquired_refs before
BPF_EXIT) on top of caller reference_state before returning (at which
point the caller and callback state will match anyway, so no need to
copy it back to caller). |
| In the Linux kernel, the following vulnerability has been resolved:
ftrace: Fix recursive locking direct_mutex in ftrace_modify_direct_caller
Naveen reported recursive locking of direct_mutex with sample
ftrace-direct-modify.ko:
[ 74.762406] WARNING: possible recursive locking detected
[ 74.762887] 6.0.0-rc6+ #33 Not tainted
[ 74.763216] --------------------------------------------
[ 74.763672] event-sample-fn/1084 is trying to acquire lock:
[ 74.764152] ffffffff86c9d6b0 (direct_mutex){+.+.}-{3:3}, at: \
register_ftrace_function+0x1f/0x180
[ 74.764922]
[ 74.764922] but task is already holding lock:
[ 74.765421] ffffffff86c9d6b0 (direct_mutex){+.+.}-{3:3}, at: \
modify_ftrace_direct+0x34/0x1f0
[ 74.766142]
[ 74.766142] other info that might help us debug this:
[ 74.766701] Possible unsafe locking scenario:
[ 74.766701]
[ 74.767216] CPU0
[ 74.767437] ----
[ 74.767656] lock(direct_mutex);
[ 74.767952] lock(direct_mutex);
[ 74.768245]
[ 74.768245] *** DEADLOCK ***
[ 74.768245]
[ 74.768750] May be due to missing lock nesting notation
[ 74.768750]
[ 74.769332] 1 lock held by event-sample-fn/1084:
[ 74.769731] #0: ffffffff86c9d6b0 (direct_mutex){+.+.}-{3:3}, at: \
modify_ftrace_direct+0x34/0x1f0
[ 74.770496]
[ 74.770496] stack backtrace:
[ 74.770884] CPU: 4 PID: 1084 Comm: event-sample-fn Not tainted ...
[ 74.771498] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), ...
[ 74.772474] Call Trace:
[ 74.772696] <TASK>
[ 74.772896] dump_stack_lvl+0x44/0x5b
[ 74.773223] __lock_acquire.cold.74+0xac/0x2b7
[ 74.773616] lock_acquire+0xd2/0x310
[ 74.773936] ? register_ftrace_function+0x1f/0x180
[ 74.774357] ? lock_is_held_type+0xd8/0x130
[ 74.774744] ? my_tramp2+0x11/0x11 [ftrace_direct_modify]
[ 74.775213] __mutex_lock+0x99/0x1010
[ 74.775536] ? register_ftrace_function+0x1f/0x180
[ 74.775954] ? slab_free_freelist_hook.isra.43+0x115/0x160
[ 74.776424] ? ftrace_set_hash+0x195/0x220
[ 74.776779] ? register_ftrace_function+0x1f/0x180
[ 74.777194] ? kfree+0x3e1/0x440
[ 74.777482] ? my_tramp2+0x11/0x11 [ftrace_direct_modify]
[ 74.777941] ? __schedule+0xb40/0xb40
[ 74.778258] ? register_ftrace_function+0x1f/0x180
[ 74.778672] ? my_tramp1+0xf/0xf [ftrace_direct_modify]
[ 74.779128] register_ftrace_function+0x1f/0x180
[ 74.779527] ? ftrace_set_filter_ip+0x33/0x70
[ 74.779910] ? __schedule+0xb40/0xb40
[ 74.780231] ? my_tramp1+0xf/0xf [ftrace_direct_modify]
[ 74.780678] ? my_tramp2+0x11/0x11 [ftrace_direct_modify]
[ 74.781147] ftrace_modify_direct_caller+0x5b/0x90
[ 74.781563] ? 0xffffffffa0201000
[ 74.781859] ? my_tramp1+0xf/0xf [ftrace_direct_modify]
[ 74.782309] modify_ftrace_direct+0x1b2/0x1f0
[ 74.782690] ? __schedule+0xb40/0xb40
[ 74.783014] ? simple_thread+0x2a/0xb0 [ftrace_direct_modify]
[ 74.783508] ? __schedule+0xb40/0xb40
[ 74.783832] ? my_tramp2+0x11/0x11 [ftrace_direct_modify]
[ 74.784294] simple_thread+0x76/0xb0 [ftrace_direct_modify]
[ 74.784766] kthread+0xf5/0x120
[ 74.785052] ? kthread_complete_and_exit+0x20/0x20
[ 74.785464] ret_from_fork+0x22/0x30
[ 74.785781] </TASK>
Fix this by using register_ftrace_function_nolock in
ftrace_modify_direct_caller. |
| In the Linux kernel, the following vulnerability has been resolved:
mmc: core: Fix kernel panic when remove non-standard SDIO card
SDIO tuple is only allocated for standard SDIO card, especially it causes
memory corruption issues when the non-standard SDIO card has removed, which
is because the card device's reference counter does not increase for it at
sdio_init_func(), but all SDIO card device reference counter gets decreased
at sdio_release_func(). |
| In the Linux kernel, the following vulnerability has been resolved:
dccp: Fix out of bounds access in DCCP error handler
There was a previous attempt to fix an out-of-bounds access in the DCCP
error handlers, but that fix assumed that the error handlers only want
to access the first 8 bytes of the DCCP header. Actually, they also look
at the DCCP sequence number, which is stored beyond 8 bytes, so an
explicit pskb_may_pull() is required. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: hpsa: Fix possible memory leak in hpsa_init_one()
The hpda_alloc_ctlr_info() allocates h and its field reply_map. However, in
hpsa_init_one(), if alloc_percpu() failed, the hpsa_init_one() jumps to
clean1 directly, which frees h and leaks the h->reply_map.
Fix by calling hpda_free_ctlr_info() to release h->replay_map and h instead
free h directly. |
| In the Linux kernel, the following vulnerability has been resolved:
cpufreq: qcom-hw: Fix memory leak in qcom_cpufreq_hw_read_lut()
If "cpu_dev" fails to get opp table in qcom_cpufreq_hw_read_lut(),
the program will return, resulting in "table" resource is not released. |
| In the Linux kernel, the following vulnerability has been resolved:
perf tool x86: Fix perf_env memory leak
Found by leak sanitizer:
```
==1632594==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 21 byte(s) in 1 object(s) allocated from:
#0 0x7f2953a7077b in __interceptor_strdup ../../../../src/libsanitizer/asan/asan_interceptors.cpp:439
#1 0x556701d6fbbf in perf_env__read_cpuid util/env.c:369
#2 0x556701d70589 in perf_env__cpuid util/env.c:465
#3 0x55670204bba2 in x86__is_amd_cpu arch/x86/util/env.c:14
#4 0x5567020487a2 in arch__post_evsel_config arch/x86/util/evsel.c:83
#5 0x556701d8f78b in evsel__config util/evsel.c:1366
#6 0x556701ef5872 in evlist__config util/record.c:108
#7 0x556701cd6bcd in test__PERF_RECORD tests/perf-record.c:112
#8 0x556701cacd07 in run_test tests/builtin-test.c:236
#9 0x556701cacfac in test_and_print tests/builtin-test.c:265
#10 0x556701cadddb in __cmd_test tests/builtin-test.c:402
#11 0x556701caf2aa in cmd_test tests/builtin-test.c:559
#12 0x556701d3b557 in run_builtin tools/perf/perf.c:323
#13 0x556701d3bac8 in handle_internal_command tools/perf/perf.c:377
#14 0x556701d3be90 in run_argv tools/perf/perf.c:421
#15 0x556701d3c3f8 in main tools/perf/perf.c:537
#16 0x7f2952a46189 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
SUMMARY: AddressSanitizer: 21 byte(s) leaked in 1 allocation(s).
``` |
