In the Linux kernel, the following vulnerability has been resolved:
mtd: core: fix possible resource leak in init_mtd()
I got the error report while inject fault in init_mtd():
sysfs: cannot create duplicate filename '/devices/virtual/bdi/mtd-0'
Call Trace:
<TASK>
dump_stack_lvl+0x67/0x83
sysfs_warn_dup+0x60/0x70
sysfs_create_dir_ns+0x109/0x120
kobject_add_internal+0xce/0x2f0
kobject_add+0x98/0x110
device_add+0x179/0xc00
device_create_groups_vargs+0xf4/0x100
device_create+0x7b/0xb0
bdi_register_va.part.13+0x58/0x2d0
bdi_register+0x9b/0xb0
init_mtd+0x62/0x171 [mtd]
do_one_initcall+0x6c/0x3c0
do_init_module+0x58/0x222
load_module+0x268e/0x27d0
__do_sys_finit_module+0xd5/0x140
do_syscall_64+0x37/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
</TASK>
kobject_add_internal failed for mtd-0 with -EEXIST, don't try to register
things with the same name in the same directory.
Error registering mtd class or bdi: -17
If init_mtdchar() fails in init_mtd(), mtd_bdi will not be unregistered,
as a result, we can't load the mtd module again, to fix this by calling
bdi_unregister(mtd_bdi) after out_procfs label.
In the Linux kernel, the following vulnerability has been resolved:
qlcnic: prevent ->dcb use-after-free on qlcnic_dcb_enable() failure
adapter->dcb would get silently freed inside qlcnic_dcb_enable() in
case qlcnic_dcb_attach() would return an error, which always happens
under OOM conditions. This would lead to use-after-free because both
of the existing callers invoke qlcnic_dcb_get_info() on the obtained
pointer, which is potentially freed at that point.
Propagate errors from qlcnic_dcb_enable(), and instead free the dcb
pointer at callsite using qlcnic_dcb_free(). This also removes the now
unused qlcnic_clear_dcb_ops() helper, which was a simple wrapper around
kfree() also causing memory leaks for partially initialized dcb.
Found by Linux Verification Center (linuxtesting.org) with the SVACE
static analysis tool.
In the Linux kernel, the following vulnerability has been resolved:
kcm: annotate data-races around kcm->rx_psock
kcm->rx_psock can be read locklessly in kcm_rfree().
Annotate the read and writes accordingly.
We do the same for kcm->rx_wait in the following patch.
syzbot reported:
BUG: KCSAN: data-race in kcm_rfree / unreserve_rx_kcm
write to 0xffff888123d827b8 of 8 bytes by task 2758 on cpu 1:
unreserve_rx_kcm+0x72/0x1f0 net/kcm/kcmsock.c:313
kcm_rcv_strparser+0x2b5/0x3a0 net/kcm/kcmsock.c:373
__strp_recv+0x64c/0xd20 net/strparser/strparser.c:301
strp_recv+0x6d/0x80 net/strparser/strparser.c:335
tcp_read_sock+0x13e/0x5a0 net/ipv4/tcp.c:1703
strp_read_sock net/strparser/strparser.c:358 [inline]
do_strp_work net/strparser/strparser.c:406 [inline]
strp_work+0xe8/0x180 net/strparser/strparser.c:415
process_one_work+0x3d3/0x720 kernel/workqueue.c:2289
worker_thread+0x618/0xa70 kernel/workqueue.c:2436
kthread+0x1a9/0x1e0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
read to 0xffff888123d827b8 of 8 bytes by task 5859 on cpu 0:
kcm_rfree+0x14c/0x220 net/kcm/kcmsock.c:181
skb_release_head_state+0x8e/0x160 net/core/skbuff.c:841
skb_release_all net/core/skbuff.c:852 [inline]
__kfree_skb net/core/skbuff.c:868 [inline]
kfree_skb_reason+0x5c/0x260 net/core/skbuff.c:891
kfree_skb include/linux/skbuff.h:1216 [inline]
kcm_recvmsg+0x226/0x2b0 net/kcm/kcmsock.c:1161
____sys_recvmsg+0x16c/0x2e0
___sys_recvmsg net/socket.c:2743 [inline]
do_recvmmsg+0x2f1/0x710 net/socket.c:2837
__sys_recvmmsg net/socket.c:2916 [inline]
__do_sys_recvmmsg net/socket.c:2939 [inline]
__se_sys_recvmmsg net/socket.c:2932 [inline]
__x64_sys_recvmmsg+0xde/0x160 net/socket.c:2932
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
value changed: 0xffff88812971ce00 -> 0x0000000000000000
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 5859 Comm: syz-executor.3 Not tainted 6.0.0-syzkaller-12189-g19d17ab7c68b-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
In the Linux kernel, the following vulnerability has been resolved:
btrfs: do not BUG_ON() on ENOMEM when dropping extent items for a range
If we get -ENOMEM while dropping file extent items in a given range, at
btrfs_drop_extents(), due to failure to allocate memory when attempting to
increment the reference count for an extent or drop the reference count,
we handle it with a BUG_ON(). This is excessive, instead we can simply
abort the transaction and return the error to the caller. In fact most
callers of btrfs_drop_extents(), directly or indirectly, already abort
the transaction if btrfs_drop_extents() returns any error.
Also, we already have error paths at btrfs_drop_extents() that may return
-ENOMEM and in those cases we abort the transaction, like for example
anything that changes the b+tree may return -ENOMEM due to a failure to
allocate a new extent buffer when COWing an existing extent buffer, such
as a call to btrfs_duplicate_item() for example.
So replace the BUG_ON() calls with proper logic to abort the transaction
and return the error.
In the Linux kernel, the following vulnerability has been resolved:
wifi: libertas: fix memory leak in lbs_init_adapter()
When kfifo_alloc() failed in lbs_init_adapter(), cmd buffer is not
released. Add free memory to processing error path.
In the Linux kernel, the following vulnerability has been resolved:
pnode: terminate at peers of source
The propagate_mnt() function handles mount propagation when creating
mounts and propagates the source mount tree @source_mnt to all
applicable nodes of the destination propagation mount tree headed by
@dest_mnt.
Unfortunately it contains a bug where it fails to terminate at peers of
@source_mnt when looking up copies of the source mount that become
masters for copies of the source mount tree mounted on top of slaves in
the destination propagation tree causing a NULL dereference.
Once the mechanics of the bug are understood it's easy to trigger.
Because of unprivileged user namespaces it is available to unprivileged
users.
While fixing this bug we've gotten confused multiple times due to
unclear terminology or missing concepts. So let's start this with some
clarifications:
* The terms "master" or "peer" denote a shared mount. A shared mount
belongs to a peer group.
* A peer group is a set of shared mounts that propagate to each other.
They are identified by a peer group id. The peer group id is available
in @shared_mnt->mnt_group_id.
Shared mounts within the same peer group have the same peer group id.
The peers in a peer group can be reached via @shared_mnt->mnt_share.
* The terms "slave mount" or "dependent mount" denote a mount that
receives propagation from a peer in a peer group. IOW, shared mounts
may have slave mounts and slave mounts have shared mounts as their
master. Slave mounts of a given peer in a peer group are listed on
that peers slave list available at @shared_mnt->mnt_slave_list.
* The term "master mount" denotes a mount in a peer group. IOW, it
denotes a shared mount or a peer mount in a peer group. The term
"master mount" - or "master" for short - is mostly used when talking
in the context of slave mounts that receive propagation from a master
mount. A master mount of a slave identifies the closest peer group a
slave mount receives propagation from. The master mount of a slave can
be identified via @slave_mount->mnt_master. Different slaves may point
to different masters in the same peer group.
* Multiple peers in a peer group can have non-empty ->mnt_slave_lists.
Non-empty ->mnt_slave_lists of peers don't intersect. Consequently, to
ensure all slave mounts of a peer group are visited the
->mnt_slave_lists of all peers in a peer group have to be walked.
* Slave mounts point to a peer in the closest peer group they receive
propagation from via @slave_mnt->mnt_master (see above). Together with
these peers they form a propagation group (see below). The closest
peer group can thus be identified through the peer group id
@slave_mnt->mnt_master->mnt_group_id of the peer/master that a slave
mount receives propagation from.
* A shared-slave mount is a slave mount to a peer group pg1 while also
a peer in another peer group pg2. IOW, a peer group may receive
propagation from another peer group.
If a peer group pg1 is a slave to another peer group pg2 then all
peers in peer group pg1 point to the same peer in peer group pg2 via
->mnt_master. IOW, all peers in peer group pg1 appear on the same
->mnt_slave_list. IOW, they cannot be slaves to different peer groups.
* A pure slave mount is a slave mount that is a slave to a peer group
but is not a peer in another peer group.
* A propagation group denotes the set of mounts consisting of a single
peer group pg1 and all slave mounts and shared-slave mounts that point
to a peer in that peer group via ->mnt_master. IOW, all slave mounts
such that @slave_mnt->mnt_master->mnt_group_id is equal to
@shared_mnt->mnt_group_id.
The concept of a propagation group makes it easier to talk about a
single propagation level in a propagation tree.
For example, in propagate_mnt() the immediate peers of @dest_mnt and
all slaves of @dest_mnt's peer group form a propagation group pr
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
chardev: fix error handling in cdev_device_add()
While doing fault injection test, I got the following report:
------------[ cut here ]------------
kobject: '(null)' (0000000039956980): is not initialized, yet kobject_put() is being called.
WARNING: CPU: 3 PID: 6306 at kobject_put+0x23d/0x4e0
CPU: 3 PID: 6306 Comm: 283 Tainted: G W 6.1.0-rc2-00005-g307c1086d7c9 #1253
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:kobject_put+0x23d/0x4e0
Call Trace:
<TASK>
cdev_device_add+0x15e/0x1b0
__iio_device_register+0x13b4/0x1af0 [industrialio]
__devm_iio_device_register+0x22/0x90 [industrialio]
max517_probe+0x3d8/0x6b4 [max517]
i2c_device_probe+0xa81/0xc00
When device_add() is injected fault and returns error, if dev->devt is not set,
cdev_add() is not called, cdev_del() is not needed. Fix this by checking dev->devt
in error path.
In the Linux kernel, the following vulnerability has been resolved:
mm,hugetlb: take hugetlb_lock before decrementing h->resv_huge_pages
The h->*_huge_pages counters are protected by the hugetlb_lock, but
alloc_huge_page has a corner case where it can decrement the counter
outside of the lock.
This could lead to a corrupted value of h->resv_huge_pages, which we have
observed on our systems.
Take the hugetlb_lock before decrementing h->resv_huge_pages to avoid a
potential race.