| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
accel/qaic: Clean up integer overflow checking in map_user_pages()
The encode_dma() function has some validation on in_trans->size but it
would be more clear to move those checks to find_and_map_user_pages().
The encode_dma() had two checks:
if (in_trans->addr + in_trans->size < in_trans->addr || !in_trans->size)
return -EINVAL;
The in_trans->addr variable is the starting address. The in_trans->size
variable is the total size of the transfer. The transfer can occur in
parts and the resources->xferred_dma_size tracks how many bytes we have
already transferred.
This patch introduces a new variable "remaining" which represents the
amount we want to transfer (in_trans->size) minus the amount we have
already transferred (resources->xferred_dma_size).
I have modified the check for if in_trans->size is zero to instead check
if in_trans->size is less than resources->xferred_dma_size. If we have
already transferred more bytes than in_trans->size then there are negative
bytes remaining which doesn't make sense. If there are zero bytes
remaining to be copied, just return success.
The check in encode_dma() checked that "addr + size" could not overflow
and barring a driver bug that should work, but it's easier to check if
we do this in parts. First check that "in_trans->addr +
resources->xferred_dma_size" is safe. Then check that "xfer_start_addr +
remaining" is safe.
My final concern was that we are dealing with u64 values but on 32bit
systems the kmalloc() function will truncate the sizes to 32 bits. So
I calculated "total = in_trans->size + offset_in_page(xfer_start_addr);"
and returned -EINVAL if it were >= SIZE_MAX. This will not affect 64bit
systems. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/irdma: Cap MSIX used to online CPUs + 1
The irdma driver can use a maximum number of msix vectors equal
to num_online_cpus() + 1 and the kernel warning stack below is shown
if that number is exceeded.
The kernel throws a warning as the driver tries to update the affinity
hint with a CPU mask greater than the max CPU IDs. Fix this by capping
the MSIX vectors to num_online_cpus() + 1.
WARNING: CPU: 7 PID: 23655 at include/linux/cpumask.h:106 irdma_cfg_ceq_vector+0x34c/0x3f0 [irdma]
RIP: 0010:irdma_cfg_ceq_vector+0x34c/0x3f0 [irdma]
Call Trace:
irdma_rt_init_hw+0xa62/0x1290 [irdma]
? irdma_alloc_local_mac_entry+0x1a0/0x1a0 [irdma]
? __is_kernel_percpu_address+0x63/0x310
? rcu_read_lock_held_common+0xe/0xb0
? irdma_lan_unregister_qset+0x280/0x280 [irdma]
? irdma_request_reset+0x80/0x80 [irdma]
? ice_get_qos_params+0x84/0x390 [ice]
irdma_probe+0xa40/0xfc0 [irdma]
? rcu_read_lock_bh_held+0xd0/0xd0
? irdma_remove+0x140/0x140 [irdma]
? rcu_read_lock_sched_held+0x62/0xe0
? down_write+0x187/0x3d0
? auxiliary_match_id+0xf0/0x1a0
? irdma_remove+0x140/0x140 [irdma]
auxiliary_bus_probe+0xa6/0x100
__driver_probe_device+0x4a4/0xd50
? __device_attach_driver+0x2c0/0x2c0
driver_probe_device+0x4a/0x110
__driver_attach+0x1aa/0x350
bus_for_each_dev+0x11d/0x1b0
? subsys_dev_iter_init+0xe0/0xe0
bus_add_driver+0x3b1/0x610
driver_register+0x18e/0x410
? 0xffffffffc0b88000
irdma_init_module+0x50/0xaa [irdma]
do_one_initcall+0x103/0x5f0
? perf_trace_initcall_level+0x420/0x420
? do_init_module+0x4e/0x700
? __kasan_kmalloc+0x7d/0xa0
? kmem_cache_alloc_trace+0x188/0x2b0
? kasan_unpoison+0x21/0x50
do_init_module+0x1d1/0x700
load_module+0x3867/0x5260
? layout_and_allocate+0x3990/0x3990
? rcu_read_lock_held_common+0xe/0xb0
? rcu_read_lock_sched_held+0x62/0xe0
? rcu_read_lock_bh_held+0xd0/0xd0
? __vmalloc_node_range+0x46b/0x890
? lock_release+0x5c8/0xba0
? alloc_vm_area+0x120/0x120
? selinux_kernel_module_from_file+0x2a5/0x300
? __inode_security_revalidate+0xf0/0xf0
? __do_sys_init_module+0x1db/0x260
__do_sys_init_module+0x1db/0x260
? load_module+0x5260/0x5260
? do_syscall_64+0x22/0x450
do_syscall_64+0xa5/0x450
entry_SYSCALL_64_after_hwframe+0x66/0xdb |
| In the Linux kernel, the following vulnerability has been resolved:
platform/x86: think-lmi: Fix memory leak when showing current settings
When retriving a item string with tlmi_setting(), the result has to be
freed using kfree(). In current_value_show() however, malformed
item strings are not freed, causing a memory leak.
Fix this by eliminating the early return responsible for this. |
| In the Linux kernel, the following vulnerability has been resolved:
blk-mq: release crypto keyslot before reporting I/O complete
Once all I/O using a blk_crypto_key has completed, filesystems can call
blk_crypto_evict_key(). However, the block layer currently doesn't call
blk_crypto_put_keyslot() until the request is being freed, which happens
after upper layers have been told (via bio_endio()) the I/O has
completed. This causes a race condition where blk_crypto_evict_key()
can see 'slot_refs != 0' without there being an actual bug.
This makes __blk_crypto_evict_key() hit the
'WARN_ON_ONCE(atomic_read(&slot->slot_refs) != 0)' and return without
doing anything, eventually causing a use-after-free in
blk_crypto_reprogram_all_keys(). (This is a very rare bug and has only
been seen when per-file keys are being used with fscrypt.)
There are two options to fix this: either release the keyslot before
bio_endio() is called on the request's last bio, or make
__blk_crypto_evict_key() ignore slot_refs. Let's go with the first
solution, since it preserves the ability to report bugs (via
WARN_ON_ONCE) where a key is evicted while still in-use. |
| In the Linux kernel, the following vulnerability has been resolved:
smc: Fix use-after-free in tcp_write_timer_handler().
With Eric's ref tracker, syzbot finally found a repro for
use-after-free in tcp_write_timer_handler() by kernel TCP
sockets. [0]
If SMC creates a kernel socket in __smc_create(), the kernel
socket is supposed to be freed in smc_clcsock_release() by
calling sock_release() when we close() the parent SMC socket.
However, at the end of smc_clcsock_release(), the kernel
socket's sk_state might not be TCP_CLOSE. This means that
we have not called inet_csk_destroy_sock() in __tcp_close()
and have not stopped the TCP timers.
The kernel socket's TCP timers can be fired later, so we
need to hold a refcnt for net as we do for MPTCP subflows
in mptcp_subflow_create_socket().
[0]:
leaked reference.
sk_alloc (./include/net/net_namespace.h:335 net/core/sock.c:2108)
inet_create (net/ipv4/af_inet.c:319 net/ipv4/af_inet.c:244)
__sock_create (net/socket.c:1546)
smc_create (net/smc/af_smc.c:3269 net/smc/af_smc.c:3284)
__sock_create (net/socket.c:1546)
__sys_socket (net/socket.c:1634 net/socket.c:1618 net/socket.c:1661)
__x64_sys_socket (net/socket.c:1672)
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)
==================================================================
BUG: KASAN: slab-use-after-free in tcp_write_timer_handler (net/ipv4/tcp_timer.c:378 net/ipv4/tcp_timer.c:624 net/ipv4/tcp_timer.c:594)
Read of size 1 at addr ffff888052b65e0d by task syzrepro/18091
CPU: 0 PID: 18091 Comm: syzrepro Tainted: G W 6.3.0-rc4-01174-gb5d54eb5899a #7
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.amzn2022.0.1 04/01/2014
Call Trace:
<IRQ>
dump_stack_lvl (lib/dump_stack.c:107)
print_report (mm/kasan/report.c:320 mm/kasan/report.c:430)
kasan_report (mm/kasan/report.c:538)
tcp_write_timer_handler (net/ipv4/tcp_timer.c:378 net/ipv4/tcp_timer.c:624 net/ipv4/tcp_timer.c:594)
tcp_write_timer (./include/linux/spinlock.h:390 net/ipv4/tcp_timer.c:643)
call_timer_fn (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/timer.h:127 kernel/time/timer.c:1701)
__run_timers.part.0 (kernel/time/timer.c:1752 kernel/time/timer.c:2022)
run_timer_softirq (kernel/time/timer.c:2037)
__do_softirq (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/irq.h:142 kernel/softirq.c:572)
__irq_exit_rcu (kernel/softirq.c:445 kernel/softirq.c:650)
irq_exit_rcu (kernel/softirq.c:664)
sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1107 (discriminator 14))
</IRQ> |
| In the Linux kernel, the following vulnerability has been resolved:
md/raid5-cache: fix a deadlock in r5l_exit_log()
Commit b13015af94cf ("md/raid5-cache: Clear conf->log after finishing
work") introduce a new problem:
// caller hold reconfig_mutex
r5l_exit_log
flush_work(&log->disable_writeback_work)
r5c_disable_writeback_async
wait_event
/*
* conf->log is not NULL, and mddev_trylock()
* will fail, wait_event() can never pass.
*/
conf->log = NULL
Fix this problem by setting 'config->log' to NULL before wake_up() as it
used to be, so that wait_event() from r5c_disable_writeback_async() can
exist. In the meantime, move forward md_unregister_thread() so that
null-ptr-deref this commit fixed can still be fixed. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix warning when putting transaction with qgroups enabled after abort
If we have a transaction abort with qgroups enabled we get a warning
triggered when doing the final put on the transaction, like this:
[552.6789] ------------[ cut here ]------------
[552.6815] WARNING: CPU: 4 PID: 81745 at fs/btrfs/transaction.c:144 btrfs_put_transaction+0x123/0x130 [btrfs]
[552.6817] Modules linked in: btrfs blake2b_generic xor (...)
[552.6819] CPU: 4 PID: 81745 Comm: btrfs-transacti Tainted: G W 6.4.0-rc6-btrfs-next-134+ #1
[552.6819] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014
[552.6819] RIP: 0010:btrfs_put_transaction+0x123/0x130 [btrfs]
[552.6821] Code: bd a0 01 00 (...)
[552.6821] RSP: 0018:ffffa168c0527e28 EFLAGS: 00010286
[552.6821] RAX: ffff936042caed00 RBX: ffff93604a3eb448 RCX: 0000000000000000
[552.6821] RDX: ffff93606421b028 RSI: ffffffff92ff0878 RDI: ffff93606421b010
[552.6821] RBP: ffff93606421b000 R08: 0000000000000000 R09: ffffa168c0d07c20
[552.6821] R10: 0000000000000000 R11: ffff93608dc52950 R12: ffffa168c0527e70
[552.6821] R13: ffff93606421b000 R14: ffff93604a3eb420 R15: ffff93606421b028
[552.6821] FS: 0000000000000000(0000) GS:ffff93675fb00000(0000) knlGS:0000000000000000
[552.6821] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[552.6821] CR2: 0000558ad262b000 CR3: 000000014feda005 CR4: 0000000000370ee0
[552.6822] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[552.6822] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[552.6822] Call Trace:
[552.6822] <TASK>
[552.6822] ? __warn+0x80/0x130
[552.6822] ? btrfs_put_transaction+0x123/0x130 [btrfs]
[552.6824] ? report_bug+0x1f4/0x200
[552.6824] ? handle_bug+0x42/0x70
[552.6824] ? exc_invalid_op+0x14/0x70
[552.6824] ? asm_exc_invalid_op+0x16/0x20
[552.6824] ? btrfs_put_transaction+0x123/0x130 [btrfs]
[552.6826] btrfs_cleanup_transaction+0xe7/0x5e0 [btrfs]
[552.6828] ? _raw_spin_unlock_irqrestore+0x23/0x40
[552.6828] ? try_to_wake_up+0x94/0x5e0
[552.6828] ? __pfx_process_timeout+0x10/0x10
[552.6828] transaction_kthread+0x103/0x1d0 [btrfs]
[552.6830] ? __pfx_transaction_kthread+0x10/0x10 [btrfs]
[552.6832] kthread+0xee/0x120
[552.6832] ? __pfx_kthread+0x10/0x10
[552.6832] ret_from_fork+0x29/0x50
[552.6832] </TASK>
[552.6832] ---[ end trace 0000000000000000 ]---
This corresponds to this line of code:
void btrfs_put_transaction(struct btrfs_transaction *transaction)
{
(...)
WARN_ON(!RB_EMPTY_ROOT(
&transaction->delayed_refs.dirty_extent_root));
(...)
}
The warning happens because btrfs_qgroup_destroy_extent_records(), called
in the transaction abort path, we free all entries from the rbtree
"dirty_extent_root" with rbtree_postorder_for_each_entry_safe(), but we
don't actually empty the rbtree - it's still pointing to nodes that were
freed.
So set the rbtree's root node to NULL to avoid this warning (assign
RB_ROOT). |
| 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:
ethtool: eeprom: fix null-deref on genl_info in dump
The similar fix as commit 46cdedf2a0fa ("ethtool: pse-pd: fix null-deref on
genl_info in dump") is also needed for ethtool eeprom. |
| In the Linux kernel, the following vulnerability has been resolved:
HSI: omap_ssi: Fix refcount leak in ssi_probe
When returning or breaking early from a
for_each_available_child_of_node() loop, we need to explicitly call
of_node_put() on the child node to possibly release the node. |
| In the Linux kernel, the following vulnerability has been resolved:
platform/chrome: cros_ec_typec: zero out stale pointers
`cros_typec_get_switch_handles` allocates four pointers when obtaining
type-c switch handles. These pointers are all freed if failing to obtain
any of them; therefore, pointers in `port` become stale. The stale
pointers eventually cause use-after-free or double free in later code
paths. Zeroing out all pointer fields after freeing to eliminate these
stale pointers. |
| In the Linux kernel, the following vulnerability has been resolved:
cifs: Fix xid leak in cifs_copy_file_range()
If the file is used by swap, before return -EOPNOTSUPP, should
free the xid, otherwise, the xid will be leaked. |
| In the Linux kernel, the following vulnerability has been resolved:
clk: ti: dra7-atl: Fix reference leak in of_dra7_atl_clk_probe
pm_runtime_get_sync() will increment pm usage counter.
Forgetting to putting operation will result in reference leak.
Add missing pm_runtime_put_sync in some error paths. |
| 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:
RISC-V: Make port I/O string accessors actually work
Fix port I/O string accessors such as `insb', `outsb', etc. which use
the physical PCI port I/O address rather than the corresponding memory
mapping to get at the requested location, which in turn breaks at least
accesses made by our parport driver to a PCIe parallel port such as:
PCI parallel port detected: 1415:c118, I/O at 0x1000(0x1008), IRQ 20
parport0: PC-style at 0x1000 (0x1008), irq 20, using FIFO [PCSPP,TRISTATE,COMPAT,EPP,ECP]
causing a memory access fault:
Unable to handle kernel access to user memory without uaccess routines at virtual address 0000000000001008
Oops [#1]
Modules linked in:
CPU: 1 PID: 350 Comm: cat Not tainted 6.0.0-rc2-00283-g10d4879f9ef0-dirty #23
Hardware name: SiFive HiFive Unmatched A00 (DT)
epc : parport_pc_fifo_write_block_pio+0x266/0x416
ra : parport_pc_fifo_write_block_pio+0xb4/0x416
epc : ffffffff80542c3e ra : ffffffff80542a8c sp : ffffffd88899fc60
gp : ffffffff80fa2700 tp : ffffffd882b1e900 t0 : ffffffd883d0b000
t1 : ffffffffff000002 t2 : 4646393043330a38 s0 : ffffffd88899fcf0
s1 : 0000000000001000 a0 : 0000000000000010 a1 : 0000000000000000
a2 : ffffffd883d0a010 a3 : 0000000000000023 a4 : 00000000ffff8fbb
a5 : ffffffd883d0a001 a6 : 0000000100000000 a7 : ffffffc800000000
s2 : ffffffffff000002 s3 : ffffffff80d28880 s4 : ffffffff80fa1f50
s5 : 0000000000001008 s6 : 0000000000000008 s7 : ffffffd883d0a000
s8 : 0004000000000000 s9 : ffffffff80dc1d80 s10: ffffffd8807e4000
s11: 0000000000000000 t3 : 00000000000000ff t4 : 393044410a303930
t5 : 0000000000001000 t6 : 0000000000040000
status: 0000000200000120 badaddr: 0000000000001008 cause: 000000000000000f
[<ffffffff80543212>] parport_pc_compat_write_block_pio+0xfe/0x200
[<ffffffff8053bbc0>] parport_write+0x46/0xf8
[<ffffffff8050530e>] lp_write+0x158/0x2d2
[<ffffffff80185716>] vfs_write+0x8e/0x2c2
[<ffffffff80185a74>] ksys_write+0x52/0xc2
[<ffffffff80185af2>] sys_write+0xe/0x16
[<ffffffff80003770>] ret_from_syscall+0x0/0x2
---[ end trace 0000000000000000 ]---
For simplicity address the problem by adding PCI_IOBASE to the physical
address requested in the respective wrapper macros only, observing that
the raw accessors such as `__insb', `__outsb', etc. are not supposed to
be used other than by said macros. Remove the cast to `long' that is no
longer needed on `addr' now that it is used as an offset from PCI_IOBASE
and add parentheses around `addr' needed for predictable evaluation in
macro expansion. No need to make said adjustments in separate changes
given that current code is gravely broken and does not ever work. |
| 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:
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:
RDMA/siw: Fix QP destroy to wait for all references dropped.
Delay QP destroy completion until all siw references to QP are
dropped. The calling RDMA core will free QP structure after
successful return from siw_qp_destroy() call, so siw must not
hold any remaining reference to the QP upon return.
A use-after-free was encountered in xfstest generic/460, while
testing NFSoRDMA. Here, after a TCP connection drop by peer,
the triggered siw_cm_work_handler got delayed until after
QP destroy call, referencing a QP which has already freed. |
| 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:
ext4: fix deadlock due to mbcache entry corruption
When manipulating xattr blocks, we can deadlock infinitely looping
inside ext4_xattr_block_set() where we constantly keep finding xattr
block for reuse in mbcache but we are unable to reuse it because its
reference count is too big. This happens because cache entry for the
xattr block is marked as reusable (e_reusable set) although its
reference count is too big. When this inconsistency happens, this
inconsistent state is kept indefinitely and so ext4_xattr_block_set()
keeps retrying indefinitely.
The inconsistent state is caused by non-atomic update of e_reusable bit.
e_reusable is part of a bitfield and e_reusable update can race with
update of e_referenced bit in the same bitfield resulting in loss of one
of the updates. Fix the problem by using atomic bitops instead.
This bug has been around for many years, but it became *much* easier
to hit after commit 65f8b80053a1 ("ext4: fix race when reusing xattr
blocks"). |
