| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: fix out-of-bound read in ext4_xattr_inode_dec_ref_all()
There's issue as follows:
BUG: KASAN: use-after-free in ext4_xattr_inode_dec_ref_all+0x6ff/0x790
Read of size 4 at addr ffff88807b003000 by task syz-executor.0/15172
CPU: 3 PID: 15172 Comm: syz-executor.0
Call Trace:
__dump_stack lib/dump_stack.c:82 [inline]
dump_stack+0xbe/0xfd lib/dump_stack.c:123
print_address_description.constprop.0+0x1e/0x280 mm/kasan/report.c:400
__kasan_report.cold+0x6c/0x84 mm/kasan/report.c:560
kasan_report+0x3a/0x50 mm/kasan/report.c:585
ext4_xattr_inode_dec_ref_all+0x6ff/0x790 fs/ext4/xattr.c:1137
ext4_xattr_delete_inode+0x4c7/0xda0 fs/ext4/xattr.c:2896
ext4_evict_inode+0xb3b/0x1670 fs/ext4/inode.c:323
evict+0x39f/0x880 fs/inode.c:622
iput_final fs/inode.c:1746 [inline]
iput fs/inode.c:1772 [inline]
iput+0x525/0x6c0 fs/inode.c:1758
ext4_orphan_cleanup fs/ext4/super.c:3298 [inline]
ext4_fill_super+0x8c57/0xba40 fs/ext4/super.c:5300
mount_bdev+0x355/0x410 fs/super.c:1446
legacy_get_tree+0xfe/0x220 fs/fs_context.c:611
vfs_get_tree+0x8d/0x2f0 fs/super.c:1576
do_new_mount fs/namespace.c:2983 [inline]
path_mount+0x119a/0x1ad0 fs/namespace.c:3316
do_mount+0xfc/0x110 fs/namespace.c:3329
__do_sys_mount fs/namespace.c:3540 [inline]
__se_sys_mount+0x219/0x2e0 fs/namespace.c:3514
do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x67/0xd1
Memory state around the buggy address:
ffff88807b002f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88807b002f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88807b003000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff88807b003080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88807b003100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
Above issue happens as ext4_xattr_delete_inode() isn't check xattr
is valid if xattr is in inode.
To solve above issue call xattr_check_inode() check if xattr if valid
in inode. In fact, we can directly verify in ext4_iget_extra_inode(),
so that there is no divergent verification. |
| In the Linux kernel, the following vulnerability has been resolved:
Revert "smb: client: fix TCP timers deadlock after rmmod"
This reverts commit e9f2517a3e18a54a3943c098d2226b245d488801.
Commit e9f2517a3e18 ("smb: client: fix TCP timers deadlock after
rmmod") is intended to fix a null-ptr-deref in LOCKDEP, which is
mentioned as CVE-2024-54680, but is actually did not fix anything;
The issue can be reproduced on top of it. [0]
Also, it reverted the change by commit ef7134c7fc48 ("smb: client:
Fix use-after-free of network namespace.") and introduced a real
issue by reviving the kernel TCP socket.
When a reconnect happens for a CIFS connection, the socket state
transitions to FIN_WAIT_1. Then, inet_csk_clear_xmit_timers_sync()
in tcp_close() stops all timers for the socket.
If an incoming FIN packet is lost, the socket will stay at FIN_WAIT_1
forever, and such sockets could be leaked up to net.ipv4.tcp_max_orphans.
Usually, FIN can be retransmitted by the peer, but if the peer aborts
the connection, the issue comes into reality.
I warned about this privately by pointing out the exact report [1],
but the bogus fix was finally merged.
So, we should not stop the timers to finally kill the connection on
our side in that case, meaning we must not use a kernel socket for
TCP whose sk->sk_net_refcnt is 0.
The kernel socket does not have a reference to its netns to make it
possible to tear down netns without cleaning up every resource in it.
For example, tunnel devices use a UDP socket internally, but we can
destroy netns without removing such devices and let it complete
during exit. Otherwise, netns would be leaked when the last application
died.
However, this is problematic for TCP sockets because TCP has timers to
close the connection gracefully even after the socket is close()d. The
lifetime of the socket and its netns is different from the lifetime of
the underlying connection.
If the socket user does not maintain the netns lifetime, the timer could
be fired after the socket is close()d and its netns is freed up, resulting
in use-after-free.
Actually, we have seen so many similar issues and converted such sockets
to have a reference to netns.
That's why I converted the CIFS client socket to have a reference to
netns (sk->sk_net_refcnt == 1), which is somehow mentioned as out-of-scope
of CIFS and technically wrong in e9f2517a3e18, but **is in-scope and right
fix**.
Regarding the LOCKDEP issue, we can prevent the module unload by
bumping the module refcount when switching the LOCKDDEP key in
sock_lock_init_class_and_name(). [2]
For a while, let's revert the bogus fix.
Note that now we can use sk_net_refcnt_upgrade() for the socket
conversion, but I'll do so later separately to make backport easy. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: add mutual exclusion in proc_sctp_do_udp_port()
We must serialize calls to sctp_udp_sock_stop() and sctp_udp_sock_start()
or risk a crash as syzbot reported:
Oops: general protection fault, probably for non-canonical address 0xdffffc000000000d: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f]
CPU: 1 UID: 0 PID: 6551 Comm: syz.1.44 Not tainted 6.14.0-syzkaller-g7f2ff7b62617 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:kernel_sock_shutdown+0x47/0x70 net/socket.c:3653
Call Trace:
<TASK>
udp_tunnel_sock_release+0x68/0x80 net/ipv4/udp_tunnel_core.c:181
sctp_udp_sock_stop+0x71/0x160 net/sctp/protocol.c:930
proc_sctp_do_udp_port+0x264/0x450 net/sctp/sysctl.c:553
proc_sys_call_handler+0x3d0/0x5b0 fs/proc/proc_sysctl.c:601
iter_file_splice_write+0x91c/0x1150 fs/splice.c:738
do_splice_from fs/splice.c:935 [inline]
direct_splice_actor+0x18f/0x6c0 fs/splice.c:1158
splice_direct_to_actor+0x342/0xa30 fs/splice.c:1102
do_splice_direct_actor fs/splice.c:1201 [inline]
do_splice_direct+0x174/0x240 fs/splice.c:1227
do_sendfile+0xafd/0xe50 fs/read_write.c:1368
__do_sys_sendfile64 fs/read_write.c:1429 [inline]
__se_sys_sendfile64 fs/read_write.c:1415 [inline]
__x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1415
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] |
| In the Linux kernel, the following vulnerability has been resolved:
nfsd: put dl_stid if fail to queue dl_recall
Before calling nfsd4_run_cb to queue dl_recall to the callback_wq, we
increment the reference count of dl_stid.
We expect that after the corresponding work_struct is processed, the
reference count of dl_stid will be decremented through the callback
function nfsd4_cb_recall_release.
However, if the call to nfsd4_run_cb fails, the incremented reference
count of dl_stid will not be decremented correspondingly, leading to the
following nfs4_stid leak:
unreferenced object 0xffff88812067b578 (size 344):
comm "nfsd", pid 2761, jiffies 4295044002 (age 5541.241s)
hex dump (first 32 bytes):
01 00 00 00 6b 6b 6b 6b b8 02 c0 e2 81 88 ff ff ....kkkk........
00 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 ad 4e ad de .kkkkkkk.....N..
backtrace:
kmem_cache_alloc+0x4b9/0x700
nfsd4_process_open1+0x34/0x300
nfsd4_open+0x2d1/0x9d0
nfsd4_proc_compound+0x7a2/0xe30
nfsd_dispatch+0x241/0x3e0
svc_process_common+0x5d3/0xcc0
svc_process+0x2a3/0x320
nfsd+0x180/0x2e0
kthread+0x199/0x1d0
ret_from_fork+0x30/0x50
ret_from_fork_asm+0x1b/0x30
unreferenced object 0xffff8881499f4d28 (size 368):
comm "nfsd", pid 2761, jiffies 4295044005 (age 5541.239s)
hex dump (first 32 bytes):
01 00 00 00 00 00 00 00 30 4d 9f 49 81 88 ff ff ........0M.I....
30 4d 9f 49 81 88 ff ff 20 00 00 00 01 00 00 00 0M.I.... .......
backtrace:
kmem_cache_alloc+0x4b9/0x700
nfs4_alloc_stid+0x29/0x210
alloc_init_deleg+0x92/0x2e0
nfs4_set_delegation+0x284/0xc00
nfs4_open_delegation+0x216/0x3f0
nfsd4_process_open2+0x2b3/0xee0
nfsd4_open+0x770/0x9d0
nfsd4_proc_compound+0x7a2/0xe30
nfsd_dispatch+0x241/0x3e0
svc_process_common+0x5d3/0xcc0
svc_process+0x2a3/0x320
nfsd+0x180/0x2e0
kthread+0x199/0x1d0
ret_from_fork+0x30/0x50
ret_from_fork_asm+0x1b/0x30
Fix it by checking the result of nfsd4_run_cb and call nfs4_put_stid if
fail to queue dl_recall. |
| In the Linux kernel, the following vulnerability has been resolved:
net_sched: Prevent creation of classes with TC_H_ROOT
The function qdisc_tree_reduce_backlog() uses TC_H_ROOT as a termination
condition when traversing up the qdisc tree to update parent backlog
counters. However, if a class is created with classid TC_H_ROOT, the
traversal terminates prematurely at this class instead of reaching the
actual root qdisc, causing parent statistics to be incorrectly maintained.
In case of DRR, this could lead to a crash as reported by Mingi Cho.
Prevent the creation of any Qdisc class with classid TC_H_ROOT
(0xFFFFFFFF) across all qdisc types, as suggested by Jamal. |
| In the Linux kernel, the following vulnerability has been resolved:
net: hns3: make sure ptp clock is unregister and freed if hclge_ptp_get_cycle returns an error
During the initialization of ptp, hclge_ptp_get_cycle might return an error
and returned directly without unregister clock and free it. To avoid that,
call hclge_ptp_destroy_clock to unregist and free clock if
hclge_ptp_get_cycle failed. |
| In the Linux kernel, the following vulnerability has been resolved:
tracing: Fix bad hist from corrupting named_triggers list
The following commands causes a crash:
~# cd /sys/kernel/tracing/events/rcu/rcu_callback
~# echo 'hist:name=bad:keys=common_pid:onmax(bogus).save(common_pid)' > trigger
bash: echo: write error: Invalid argument
~# echo 'hist:name=bad:keys=common_pid' > trigger
Because the following occurs:
event_trigger_write() {
trigger_process_regex() {
event_hist_trigger_parse() {
data = event_trigger_alloc(..);
event_trigger_register(.., data) {
cmd_ops->reg(.., data, ..) [hist_register_trigger()] {
data->ops->init() [event_hist_trigger_init()] {
save_named_trigger(name, data) {
list_add(&data->named_list, &named_triggers);
}
}
}
}
ret = create_actions(); (return -EINVAL)
if (ret)
goto out_unreg;
[..]
ret = hist_trigger_enable(data, ...) {
list_add_tail_rcu(&data->list, &file->triggers); <<<---- SKIPPED!!! (this is important!)
[..]
out_unreg:
event_hist_unregister(.., data) {
cmd_ops->unreg(.., data, ..) [hist_unregister_trigger()] {
list_for_each_entry(iter, &file->triggers, list) {
if (!hist_trigger_match(data, iter, named_data, false)) <- never matches
continue;
[..]
test = iter;
}
if (test && test->ops->free) <<<-- test is NULL
test->ops->free(test) [event_hist_trigger_free()] {
[..]
if (data->name)
del_named_trigger(data) {
list_del(&data->named_list); <<<<-- NEVER gets removed!
}
}
}
}
[..]
kfree(data); <<<-- frees item but it is still on list
The next time a hist with name is registered, it causes an u-a-f bug and
the kernel can crash.
Move the code around such that if event_trigger_register() succeeds, the
next thing called is hist_trigger_enable() which adds it to the list.
A bunch of actions is called if get_named_trigger_data() returns false.
But that doesn't need to be called after event_trigger_register(), so it
can be moved up, allowing event_trigger_register() to be called just
before hist_trigger_enable() keeping them together and allowing the
file->triggers to be properly populated. |
| In the Linux kernel, the following vulnerability has been resolved:
perf/core: Add RCU read lock protection to perf_iterate_ctx()
The perf_iterate_ctx() function performs RCU list traversal but
currently lacks RCU read lock protection. This causes lockdep warnings
when running perf probe with unshare(1) under CONFIG_PROVE_RCU_LIST=y:
WARNING: suspicious RCU usage
kernel/events/core.c:8168 RCU-list traversed in non-reader section!!
Call Trace:
lockdep_rcu_suspicious
? perf_event_addr_filters_apply
perf_iterate_ctx
perf_event_exec
begin_new_exec
? load_elf_phdrs
load_elf_binary
? lock_acquire
? find_held_lock
? bprm_execve
bprm_execve
do_execveat_common.isra.0
__x64_sys_execve
do_syscall_64
entry_SYSCALL_64_after_hwframe
This protection was previously present but was removed in commit
bd2756811766 ("perf: Rewrite core context handling"). Add back the
necessary rcu_read_lock()/rcu_read_unlock() pair around
perf_iterate_ctx() call in perf_event_exec().
[ mingo: Use scoped_guard() as suggested by Peter ] |
| In the Linux kernel, the following vulnerability has been resolved:
net: better track kernel sockets lifetime
While kernel sockets are dismantled during pernet_operations->exit(),
their freeing can be delayed by any tx packets still held in qdisc
or device queues, due to skb_set_owner_w() prior calls.
This then trigger the following warning from ref_tracker_dir_exit() [1]
To fix this, make sure that kernel sockets own a reference on net->passive.
Add sk_net_refcnt_upgrade() helper, used whenever a kernel socket
is converted to a refcounted one.
[1]
[ 136.263918][ T35] ref_tracker: net notrefcnt@ffff8880638f01e0 has 1/2 users at
[ 136.263918][ T35] sk_alloc+0x2b3/0x370
[ 136.263918][ T35] inet6_create+0x6ce/0x10f0
[ 136.263918][ T35] __sock_create+0x4c0/0xa30
[ 136.263918][ T35] inet_ctl_sock_create+0xc2/0x250
[ 136.263918][ T35] igmp6_net_init+0x39/0x390
[ 136.263918][ T35] ops_init+0x31e/0x590
[ 136.263918][ T35] setup_net+0x287/0x9e0
[ 136.263918][ T35] copy_net_ns+0x33f/0x570
[ 136.263918][ T35] create_new_namespaces+0x425/0x7b0
[ 136.263918][ T35] unshare_nsproxy_namespaces+0x124/0x180
[ 136.263918][ T35] ksys_unshare+0x57d/0xa70
[ 136.263918][ T35] __x64_sys_unshare+0x38/0x40
[ 136.263918][ T35] do_syscall_64+0xf3/0x230
[ 136.263918][ T35] entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 136.263918][ T35]
[ 136.343488][ T35] ref_tracker: net notrefcnt@ffff8880638f01e0 has 1/2 users at
[ 136.343488][ T35] sk_alloc+0x2b3/0x370
[ 136.343488][ T35] inet6_create+0x6ce/0x10f0
[ 136.343488][ T35] __sock_create+0x4c0/0xa30
[ 136.343488][ T35] inet_ctl_sock_create+0xc2/0x250
[ 136.343488][ T35] ndisc_net_init+0xa7/0x2b0
[ 136.343488][ T35] ops_init+0x31e/0x590
[ 136.343488][ T35] setup_net+0x287/0x9e0
[ 136.343488][ T35] copy_net_ns+0x33f/0x570
[ 136.343488][ T35] create_new_namespaces+0x425/0x7b0
[ 136.343488][ T35] unshare_nsproxy_namespaces+0x124/0x180
[ 136.343488][ T35] ksys_unshare+0x57d/0xa70
[ 136.343488][ T35] __x64_sys_unshare+0x38/0x40
[ 136.343488][ T35] do_syscall_64+0xf3/0x230
[ 136.343488][ T35] entry_SYSCALL_64_after_hwframe+0x77/0x7f |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Fix suspicious RCU usage
Commit <d74169ceb0d2> ("iommu/vt-d: Allocate DMAR fault interrupts
locally") moved the call to enable_drhd_fault_handling() to a code
path that does not hold any lock while traversing the drhd list. Fix
it by ensuring the dmar_global_lock lock is held when traversing the
drhd list.
Without this fix, the following warning is triggered:
=============================
WARNING: suspicious RCU usage
6.14.0-rc3 #55 Not tainted
-----------------------------
drivers/iommu/intel/dmar.c:2046 RCU-list traversed in non-reader section!!
other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 1
2 locks held by cpuhp/1/23:
#0: ffffffff84a67c50 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x87/0x2c0
#1: ffffffff84a6a380 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x87/0x2c0
stack backtrace:
CPU: 1 UID: 0 PID: 23 Comm: cpuhp/1 Not tainted 6.14.0-rc3 #55
Call Trace:
<TASK>
dump_stack_lvl+0xb7/0xd0
lockdep_rcu_suspicious+0x159/0x1f0
? __pfx_enable_drhd_fault_handling+0x10/0x10
enable_drhd_fault_handling+0x151/0x180
cpuhp_invoke_callback+0x1df/0x990
cpuhp_thread_fun+0x1ea/0x2c0
smpboot_thread_fn+0x1f5/0x2e0
? __pfx_smpboot_thread_fn+0x10/0x10
kthread+0x12a/0x2d0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x4a/0x60
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
Holding the lock in enable_drhd_fault_handling() triggers a lockdep splat
about a possible deadlock between dmar_global_lock and cpu_hotplug_lock.
This is avoided by not holding dmar_global_lock when calling
iommu_device_register(), which initiates the device probe process. |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring/kbuf: reallocate buf lists on upgrade
IORING_REGISTER_PBUF_RING can reuse an old struct io_buffer_list if it
was created for legacy selected buffer and has been emptied. It violates
the requirement that most of the field should stay stable after publish.
Always reallocate it instead. |
| In the Linux kernel, the following vulnerability has been resolved:
net: xdp: Disallow attaching device-bound programs in generic mode
Device-bound programs are used to support RX metadata kfuncs. These
kfuncs are driver-specific and rely on the driver context to read the
metadata. This means they can't work in generic XDP mode. However, there
is no check to disallow such programs from being attached in generic
mode, in which case the metadata kfuncs will be called in an invalid
context, leading to crashes.
Fix this by adding a check to disallow attaching device-bound programs
in generic mode. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv4: use RCU protection in __ip_rt_update_pmtu()
__ip_rt_update_pmtu() must use RCU protection to make
sure the net structure it reads does not disappear. |
| In the Linux kernel, the following vulnerability has been resolved:
ipmr: do not call mr_mfc_uses_dev() for unres entries
syzbot found that calling mr_mfc_uses_dev() for unres entries
would crash [1], because c->mfc_un.res.minvif / c->mfc_un.res.maxvif
alias to "struct sk_buff_head unresolved", which contain two pointers.
This code never worked, lets remove it.
[1]
Unable to handle kernel paging request at virtual address ffff5fff2d536613
KASAN: maybe wild-memory-access in range [0xfffefff96a9b3098-0xfffefff96a9b309f]
Modules linked in:
CPU: 1 UID: 0 PID: 7321 Comm: syz.0.16 Not tainted 6.13.0-rc7-syzkaller-g1950a0af2d55 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : mr_mfc_uses_dev net/ipv4/ipmr_base.c:290 [inline]
pc : mr_table_dump+0x5a4/0x8b0 net/ipv4/ipmr_base.c:334
lr : mr_mfc_uses_dev net/ipv4/ipmr_base.c:289 [inline]
lr : mr_table_dump+0x694/0x8b0 net/ipv4/ipmr_base.c:334
Call trace:
mr_mfc_uses_dev net/ipv4/ipmr_base.c:290 [inline] (P)
mr_table_dump+0x5a4/0x8b0 net/ipv4/ipmr_base.c:334 (P)
mr_rtm_dumproute+0x254/0x454 net/ipv4/ipmr_base.c:382
ipmr_rtm_dumproute+0x248/0x4b4 net/ipv4/ipmr.c:2648
rtnl_dump_all+0x2e4/0x4e8 net/core/rtnetlink.c:4327
rtnl_dumpit+0x98/0x1d0 net/core/rtnetlink.c:6791
netlink_dump+0x4f0/0xbc0 net/netlink/af_netlink.c:2317
netlink_recvmsg+0x56c/0xe64 net/netlink/af_netlink.c:1973
sock_recvmsg_nosec net/socket.c:1033 [inline]
sock_recvmsg net/socket.c:1055 [inline]
sock_read_iter+0x2d8/0x40c net/socket.c:1125
new_sync_read fs/read_write.c:484 [inline]
vfs_read+0x740/0x970 fs/read_write.c:565
ksys_read+0x15c/0x26c fs/read_write.c:708 |
| In the Linux kernel, the following vulnerability has been resolved:
tls: separate no-async decryption request handling from async
If we're not doing async, the handling is much simpler. There's no
reference counting, we just need to wait for the completion to wake us
up and return its result.
We should preferably also use a separate crypto_wait. I'm not seeing a
UAF as I did in the past, I think aec7961916f3 ("tls: fix race between
async notify and socket close") took care of it.
This will make the next fix easier. |
| In the Linux kernel, the following vulnerability has been resolved:
tls: stop recv() if initial process_rx_list gave us non-DATA
If we have a non-DATA record on the rx_list and another record of the
same type still on the queue, we will end up merging them:
- process_rx_list copies the non-DATA record
- we start the loop and process the first available record since it's
of the same type
- we break out of the loop since the record was not DATA
Just check the record type and jump to the end in case process_rx_list
did some work. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: consider that tail calls invalidate packet pointers
Tail-called programs could execute any of the helpers that invalidate
packet pointers. Hence, conservatively assume that each tail call
invalidates packet pointers.
Making the change in bpf_helper_changes_pkt_data() automatically makes
use of check_cfg() logic that computes 'changes_pkt_data' effect for
global sub-programs, such that the following program could be
rejected:
int tail_call(struct __sk_buff *sk)
{
bpf_tail_call_static(sk, &jmp_table, 0);
return 0;
}
SEC("tc")
int not_safe(struct __sk_buff *sk)
{
int *p = (void *)(long)sk->data;
... make p valid ...
tail_call(sk);
*p = 42; /* this is unsafe */
...
}
The tc_bpf2bpf.c:subprog_tc() needs change: mark it as a function that
can invalidate packet pointers. Otherwise, it can't be freplaced with
tailcall_freplace.c:entry_freplace() that does a tail call. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: check changes_pkt_data property for extension programs
When processing calls to global sub-programs, verifier decides whether
to invalidate all packet pointers in current state depending on the
changes_pkt_data property of the global sub-program.
Because of this, an extension program replacing a global sub-program
must be compatible with changes_pkt_data property of the sub-program
being replaced.
This commit:
- adds changes_pkt_data flag to struct bpf_prog_aux:
- this flag is set in check_cfg() for main sub-program;
- in jit_subprogs() for other sub-programs;
- modifies bpf_check_attach_btf_id() to check changes_pkt_data flag;
- moves call to check_attach_btf_id() after the call to check_cfg(),
because it needs changes_pkt_data flag to be set:
bpf_check:
... ...
- check_attach_btf_id resolve_pseudo_ldimm64
resolve_pseudo_ldimm64 --> bpf_prog_is_offloaded
bpf_prog_is_offloaded check_cfg
check_cfg + check_attach_btf_id
... ...
The following fields are set by check_attach_btf_id():
- env->ops
- prog->aux->attach_btf_trace
- prog->aux->attach_func_name
- prog->aux->attach_func_proto
- prog->aux->dst_trampoline
- prog->aux->mod
- prog->aux->saved_dst_attach_type
- prog->aux->saved_dst_prog_type
- prog->expected_attach_type
Neither of these fields are used by resolve_pseudo_ldimm64() or
bpf_prog_offload_verifier_prep() (for netronome and netdevsim
drivers), so the reordering is safe. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: track changes_pkt_data property for global functions
When processing calls to certain helpers, verifier invalidates all
packet pointers in a current state. For example, consider the
following program:
__attribute__((__noinline__))
long skb_pull_data(struct __sk_buff *sk, __u32 len)
{
return bpf_skb_pull_data(sk, len);
}
SEC("tc")
int test_invalidate_checks(struct __sk_buff *sk)
{
int *p = (void *)(long)sk->data;
if ((void *)(p + 1) > (void *)(long)sk->data_end) return TCX_DROP;
skb_pull_data(sk, 0);
*p = 42;
return TCX_PASS;
}
After a call to bpf_skb_pull_data() the pointer 'p' can't be used
safely. See function filter.c:bpf_helper_changes_pkt_data() for a list
of such helpers.
At the moment verifier invalidates packet pointers when processing
helper function calls, and does not traverse global sub-programs when
processing calls to global sub-programs. This means that calls to
helpers done from global sub-programs do not invalidate pointers in
the caller state. E.g. the program above is unsafe, but is not
rejected by verifier.
This commit fixes the omission by computing field
bpf_subprog_info->changes_pkt_data for each sub-program before main
verification pass.
changes_pkt_data should be set if:
- subprogram calls helper for which bpf_helper_changes_pkt_data
returns true;
- subprogram calls a global function,
for which bpf_subprog_info->changes_pkt_data should be set.
The verifier.c:check_cfg() pass is modified to compute this
information. The commit relies on depth first instruction traversal
done by check_cfg() and absence of recursive function calls:
- check_cfg() would eventually visit every call to subprogram S in a
state when S is fully explored;
- when S is fully explored:
- every direct helper call within S is explored
(and thus changes_pkt_data is set if needed);
- every call to subprogram S1 called by S was visited with S1 fully
explored (and thus S inherits changes_pkt_data from S1).
The downside of such approach is that dead code elimination is not
taken into account: if a helper call inside global function is dead
because of current configuration, verifier would conservatively assume
that the call occurs for the purpose of the changes_pkt_data
computation. |
| In the Linux kernel, the following vulnerability has been resolved:
powerpc/pseries/iommu: IOMMU incorrectly marks MMIO range in DDW
Power Hypervisor can possibily allocate MMIO window intersecting with
Dynamic DMA Window (DDW) range, which is over 32-bit addressing.
These MMIO pages needs to be marked as reserved so that IOMMU doesn't map
DMA buffers in this range.
The current code is not marking these pages correctly which is resulting
in LPAR to OOPS while booting. The stack is at below
BUG: Unable to handle kernel data access on read at 0xc00800005cd40000
Faulting instruction address: 0xc00000000005cdac
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
Modules linked in: af_packet rfkill ibmveth(X) lpfc(+) nvmet_fc nvmet nvme_keyring crct10dif_vpmsum nvme_fc nvme_fabrics nvme_core be2net(+) nvme_auth rtc_generic nfsd auth_rpcgss nfs_acl lockd grace sunrpc fuse configfs ip_tables x_tables xfs libcrc32c dm_service_time ibmvfc(X) scsi_transport_fc vmx_crypto gf128mul crc32c_vpmsum dm_mirror dm_region_hash dm_log dm_multipath dm_mod sd_mod scsi_dh_emc scsi_dh_rdac scsi_dh_alua t10_pi crc64_rocksoft_generic crc64_rocksoft sg crc64 scsi_mod
Supported: Yes, External
CPU: 8 PID: 241 Comm: kworker/8:1 Kdump: loaded Not tainted 6.4.0-150600.23.14-default #1 SLE15-SP6 b44ee71c81261b9e4bab5e0cde1f2ed891d5359b
Hardware name: IBM,9080-M9S POWER9 (raw) 0x4e2103 0xf000005 of:IBM,FW950.B0 (VH950_149) hv:phyp pSeries
Workqueue: events work_for_cpu_fn
NIP: c00000000005cdac LR: c00000000005e830 CTR: 0000000000000000
REGS: c00001400c9ff770 TRAP: 0300 Not tainted (6.4.0-150600.23.14-default)
MSR: 800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 24228448 XER: 00000001
CFAR: c00000000005cdd4 DAR: c00800005cd40000 DSISR: 40000000 IRQMASK: 0
GPR00: c00000000005e830 c00001400c9ffa10 c000000001987d00 c00001400c4fe800
GPR04: 0000080000000000 0000000000000001 0000000004000000 0000000000800000
GPR08: 0000000004000000 0000000000000001 c00800005cd40000 ffffffffffffffff
GPR12: 0000000084228882 c00000000a4c4f00 0000000000000010 0000080000000000
GPR16: c00001400c4fe800 0000000004000000 0800000000000000 c00000006088b800
GPR20: c00001401a7be980 c00001400eff3800 c000000002a2da68 000000000000002b
GPR24: c0000000026793a8 c000000002679368 000000000000002a c0000000026793c8
GPR28: 000008007effffff 0000080000000000 0000000000800000 c00001400c4fe800
NIP [c00000000005cdac] iommu_table_reserve_pages+0xac/0x100
LR [c00000000005e830] iommu_init_table+0x80/0x1e0
Call Trace:
[c00001400c9ffa10] [c00000000005e810] iommu_init_table+0x60/0x1e0 (unreliable)
[c00001400c9ffa90] [c00000000010356c] iommu_bypass_supported_pSeriesLP+0x9cc/0xe40
[c00001400c9ffc30] [c00000000005c300] dma_iommu_dma_supported+0xf0/0x230
[c00001400c9ffcb0] [c00000000024b0c4] dma_supported+0x44/0x90
[c00001400c9ffcd0] [c00000000024b14c] dma_set_mask+0x3c/0x80
[c00001400c9ffd00] [c0080000555b715c] be_probe+0xc4/0xb90 [be2net]
[c00001400c9ffdc0] [c000000000986f3c] local_pci_probe+0x6c/0x110
[c00001400c9ffe40] [c000000000188f28] work_for_cpu_fn+0x38/0x60
[c00001400c9ffe70] [c00000000018e454] process_one_work+0x314/0x620
[c00001400c9fff10] [c00000000018f280] worker_thread+0x2b0/0x620
[c00001400c9fff90] [c00000000019bb18] kthread+0x148/0x150
[c00001400c9fffe0] [c00000000000ded8] start_kernel_thread+0x14/0x18
There are 2 issues in the code
1. The index is "int" while the address is "unsigned long". This results in
negative value when setting the bitmap.
2. The DMA offset is page shifted but the MMIO range is used as-is (64-bit
address). MMIO address needs to be page shifted as well. |
