Linux: >> Linux Kernel >> 2.0.20 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
net/smc: reduce rtnl pressure in smc_pnet_create_pnetids_list()
Many syzbot reports show extreme rtnl pressure, and many of them hint
that smc acquires rtnl in netns creation for no good reason [1]
This patch returns early from smc_pnet_net_init()
if there is no netdevice yet.
I am not even sure why smc_pnet_create_pnetids_list() even exists,
because smc_pnet_netdev_event() is also calling
smc_pnet_add_base_pnetid() when handling NETDEV_UP event.
[1] extract of typical syzbot reports
2 locks held by syz-executor.3/12252:
#0: ffffffff8f369610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c7/0x7b0 net/core/net_namespace.c:491
#1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_create_pnetids_list net/smc/smc_pnet.c:809 [inline]
#1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_net_init+0x10a/0x1e0 net/smc/smc_pnet.c:878
2 locks held by syz-executor.4/12253:
#0: ffffffff8f369610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c7/0x7b0 net/core/net_namespace.c:491
#1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_create_pnetids_list net/smc/smc_pnet.c:809 [inline]
#1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_net_init+0x10a/0x1e0 net/smc/smc_pnet.c:878
2 locks held by syz-executor.1/12257:
#0: ffffffff8f369610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c7/0x7b0 net/core/net_namespace.c:491
#1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_create_pnetids_list net/smc/smc_pnet.c:809 [inline]
#1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_net_init+0x10a/0x1e0 net/smc/smc_pnet.c:878
2 locks held by syz-executor.2/12261:
#0: ffffffff8f369610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c7/0x7b0 net/core/net_namespace.c:491
#1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_create_pnetids_list net/smc/smc_pnet.c:809 [inline]
#1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_net_init+0x10a/0x1e0 net/smc/smc_pnet.c:878
2 locks held by syz-executor.0/12265:
#0: ffffffff8f369610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c7/0x7b0 net/core/net_namespace.c:491
#1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_create_pnetids_list net/smc/smc_pnet.c:809 [inline]
#1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_net_init+0x10a/0x1e0 net/smc/smc_pnet.c:878
2 locks held by syz-executor.3/12268:
#0: ffffffff8f369610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c7/0x7b0 net/core/net_namespace.c:491
#1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_create_pnetids_list net/smc/smc_pnet.c:809 [inline]
#1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_net_init+0x10a/0x1e0 net/smc/smc_pnet.c:878
2 locks held by syz-executor.4/12271:
#0: ffffffff8f369610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c7/0x7b0 net/core/net_namespace.c:491
#1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_create_pnetids_list net/smc/smc_pnet.c:809 [inline]
#1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_net_init+0x10a/0x1e0 net/smc/smc_pnet.c:878
2 locks held by syz-executor.1/12274:
#0: ffffffff8f369610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c7/0x7b0 net/core/net_namespace.c:491
#1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_create_pnetids_list net/smc/smc_pnet.c:809 [inline]
#1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_net_init+0x10a/0x1e0 net/smc/smc_pnet.c:878
2 locks held by syz-executor.2/12280:
#0: ffffffff8f369610 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c7/0x7b0 net/core/net_namespace.c:491
#1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_create_pnetids_list net/smc/smc_pnet.c:809 [inline]
#1: ffffffff8f375b88 (rtnl_mutex){+.+.}-{3:3}, at: smc_pnet_net_init+0x10a/0x1e0 net/smc/smc_pnet.c:878
CVSS Score
5.5
EPSS Score
0.0
Published
2024-05-19
In the Linux kernel, the following vulnerability has been resolved:
btrfs: send: handle path ref underflow in header iterate_inode_ref()
Change BUG_ON to proper error handling if building the path buffer
fails. The pointers are not printed so we don't accidentally leak kernel
addresses.
CVSS Score
3.3
EPSS Score
0.0
Published
2024-05-19
In the Linux kernel, the following vulnerability has been resolved:
btrfs: handle chunk tree lookup error in btrfs_relocate_sys_chunks()
The unhandled case in btrfs_relocate_sys_chunks() loop is a corruption,
as it could be caused only by two impossible conditions:
- at first the search key is set up to look for a chunk tree item, with
offset -1, this is an inexact search and the key->offset will contain
the correct offset upon a successful search, a valid chunk tree item
cannot have an offset -1
- after first successful search, the found_key corresponds to a chunk
item, the offset is decremented by 1 before the next loop, it's
impossible to find a chunk item there due to alignment and size
constraints
CVSS Score
5.5
EPSS Score
0.0
Published
2024-05-19
In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: check A-MSDU format more carefully
If it looks like there's another subframe in the A-MSDU
but the header isn't fully there, we can end up reading
data out of bounds, only to discard later. Make this a
bit more careful and check if the subframe header can
even be present.
CVSS Score
7.1
EPSS Score
0.0
Published
2024-05-19
In the Linux kernel, the following vulnerability has been resolved:
dma-direct: Leak pages on dma_set_decrypted() failure
On TDX it is possible for the untrusted host to cause
set_memory_encrypted() or set_memory_decrypted() to fail such that an
error is returned and the resulting memory is shared. Callers need to
take care to handle these errors to avoid returning decrypted (shared)
memory to the page allocator, which could lead to functional or security
issues.
DMA could free decrypted/shared pages if dma_set_decrypted() fails. This
should be a rare case. Just leak the pages in this case instead of
freeing them.
CVSS Score
7.1
EPSS Score
0.0
Published
2024-05-19
In the Linux kernel, the following vulnerability has been resolved:
pstore/zone: Add a null pointer check to the psz_kmsg_read
kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure. Ensure the allocation was successful
by checking the pointer validity.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-05-19
In the Linux kernel, the following vulnerability has been resolved:
pmdomain: ti: Add a null pointer check to the omap_prm_domain_init
devm_kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure. Ensure the allocation was successful
by checking the pointer validity.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-05-19
In the Linux kernel, the following vulnerability has been resolved:
fbmon: prevent division by zero in fb_videomode_from_videomode()
The expression htotal * vtotal can have a zero value on
overflow. It is necessary to prevent division by zero like in
fb_var_to_videomode().
Found by Linux Verification Center (linuxtesting.org) with Svace.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-05-19
In the Linux kernel, the following vulnerability has been resolved:
block: prevent division by zero in blk_rq_stat_sum()
The expression dst->nr_samples + src->nr_samples may
have zero value on overflow. It is necessary to add
a check to avoid division by zero.
Found by Linux Verification Center (linuxtesting.org) with Svace.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-05-19
In the Linux kernel, the following vulnerability has been resolved:
rcu/nocb: Fix WARN_ON_ONCE() in the rcu_nocb_bypass_lock()
For the kernels built with CONFIG_RCU_NOCB_CPU_DEFAULT_ALL=y and
CONFIG_RCU_LAZY=y, the following scenarios will trigger WARN_ON_ONCE()
in the rcu_nocb_bypass_lock() and rcu_nocb_wait_contended() functions:
CPU2 CPU11
kthread
rcu_nocb_cb_kthread ksys_write
rcu_do_batch vfs_write
rcu_torture_timer_cb proc_sys_write
__kmem_cache_free proc_sys_call_handler
kmemleak_free drop_caches_sysctl_handler
delete_object_full drop_slab
__delete_object shrink_slab
put_object lazy_rcu_shrink_scan
call_rcu rcu_nocb_flush_bypass
__call_rcu_commn rcu_nocb_bypass_lock
raw_spin_trylock(&rdp->nocb_bypass_lock) fail
atomic_inc(&rdp->nocb_lock_contended);
rcu_nocb_wait_contended WARN_ON_ONCE(smp_processor_id() != rdp->cpu);
WARN_ON_ONCE(atomic_read(&rdp->nocb_lock_contended)) |
|_ _ _ _ _ _ _ _ _ _same rdp and rdp->cpu != 11_ _ _ _ _ _ _ _ _ __|
Reproduce this bug with "echo 3 > /proc/sys/vm/drop_caches".
This commit therefore uses rcu_nocb_try_flush_bypass() instead of
rcu_nocb_flush_bypass() in lazy_rcu_shrink_scan(). If the nocb_bypass
queue is being flushed, then rcu_nocb_try_flush_bypass will return
directly.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-05-19