| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix double free in create_space_info() error path
When kobject_init_and_add() fails, the call chain is:
create_space_info()
-> btrfs_sysfs_add_space_info_type()
-> kobject_init_and_add()
-> failure
-> kobject_put(&space_info->kobj)
-> space_info_release()
-> kfree(space_info)
Then control returns to create_space_info():
btrfs_sysfs_add_space_info_type() returns error
-> goto out_free
-> kfree(space_info)
This causes a double free.
Keep the direct kfree(space_info) for the earlier failure path, but
after btrfs_sysfs_add_space_info_type() has called kobject_put(), let
the kobject release callback handle the cleanup. |
| In the Linux kernel, the following vulnerability has been resolved:
ip6_gre: Use cached t->net in ip6erspan_changelink().
After commit 5e72ce3e3980 ("net: ipv6: Use link netns in newlink() of
rtnl_link_ops"), ip6erspan_newlink() correctly resolves the per-netns
ip6gre hash via link_net. ip6erspan_changelink() was not converted in
that series and still uses dev_net(dev), which diverges from the
device's creation netns after IFLA_NET_NS_FD migration.
This re-inserts the tunnel into the wrong per-netns hash. The
original netns keeps a stale entry. When that netns is later
destroyed, ip6gre_exit_rtnl_net() walks the stale entry, producing a
slab-use-after-free reported by KASAN, followed by a kernel BUG at
net/core/dev.c (LIST_POISON1) in unregister_netdevice_many_notify().
Reachable from an unprivileged user namespace (unshare --user
--map-root-user --net).
ip6gre_changelink() earlier in the same file already uses the cached
t->net; only ip6erspan_changelink() has the wrong shape. |
| In the Linux kernel, the following vulnerability has been resolved:
rbd: fix null-ptr-deref when device_add_disk() fails
do_rbd_add() publishes the device with device_add() before calling
device_add_disk(). If device_add_disk() fails after device_add()
succeeds, the error path calls rbd_free_disk() directly and then later
falls through to rbd_dev_device_release(), which calls rbd_free_disk()
again. This double teardown can leave blk-mq cleanup operating on
invalid state and trigger a null-ptr-deref in
__blk_mq_free_map_and_rqs(), reached from blk_mq_free_tag_set().
Fix this by following the normal remove ordering: call device_del()
before rbd_dev_device_release() when device_add_disk() fails after
device_add(). That keeps the teardown sequence consistent and avoids
re-entering disk cleanup through the wrong path.
The bug was first flagged by an experimental analysis tool we are
developing for kernel memory-management bugs while analyzing
v6.13-rc1. The tool is still under development and is not yet publicly
available.
We reproduced the bug on v7.0 with a real Ceph backend and a QEMU x86_64
guest booted with KASAN and CONFIG_FAILSLAB enabled. The reproducer
confines failslab injections to the __add_disk() range and injects
fail-nth while mapping an RBD image through
/sys/bus/rbd/add_single_major.
On the unpatched kernel, fail-nth=4 reliably triggered the fault:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 UID: 0 PID: 273 Comm: bash Not tainted 7.0.0-01247-gd60bc1401583 #6 PREEMPT(lazy)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
RIP: 0010:__blk_mq_free_map_and_rqs+0x8c/0x240
Code: 00 00 48 8b 6b 60 41 89 f4 49 c1 e4 03 4c 01 e5 45 85 ed 0f 85 0a 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 e9 48 c1 e9 03 <80> 3c 01 00 0f 85 31 01 00 00 4c 8b 6d 00 4d 85 ed 0f 84 e2 00 00
RSP: 0018:ff1100000ab0fac8 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ff1100000c4806a0 RCX: 0000000000000000
RDX: 0000000000000002 RSI: 0000000000000000 RDI: ff1100000c4806f4
RBP: 0000000000000000 R08: 0000000000000001 R09: ffe21c000189001b
R10: ff1100000c4800df R11: ff1100006cf37be0 R12: 0000000000000000
R13: 0000000000000000 R14: ff1100000c480700 R15: ff1100000c480004
FS: 00007f0fbe8fe740(0000) GS:ff110000e5851000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe53473b2e0 CR3: 0000000012eef000 CR4: 00000000007516f0
PKRU: 55555554
Call Trace:
<TASK>
blk_mq_free_tag_set+0x77/0x460
do_rbd_add+0x1446/0x2b80
? __pfx_do_rbd_add+0x10/0x10
? lock_acquire+0x18c/0x300
? find_held_lock+0x2b/0x80
? sysfs_file_kobj+0xb6/0x1b0
? __pfx_sysfs_kf_write+0x10/0x10
kernfs_fop_write_iter+0x2f4/0x4a0
vfs_write+0x98e/0x1000
? expand_files+0x51f/0x850
? __pfx_vfs_write+0x10/0x10
ksys_write+0xf2/0x1d0
? __pfx_ksys_write+0x10/0x10
do_syscall_64+0x115/0x690
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0fbea15907
Code: 10 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
RSP: 002b:00007ffe22346ea8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000058 RCX: 00007f0fbea15907
RDX: 0000000000000058 RSI: 0000563ace6c0ef0 RDI: 0000000000000001
RBP: 0000563ace6c0ef0 R08: 0000563ace6c0ef0 R09: 6b6435726d694141
R10: 5250337279762f78 R11: 0000000000000246 R12: 0000000000000058
R13: 00007f0fbeb1c780 R14: ff1100000c480700 R15: ff1100000c480004
</TASK>
With this fix applied, rerunning the reproducer over fail-nth=1..256
yields no KASAN reports.
[ idryomov: rename err_out_device_del -> err_out_device ] |
| In the Linux kernel, the following vulnerability has been resolved:
net: rds: fix MR cleanup on copy error
__rds_rdma_map() hands sg/pages ownership to the transport after
get_mr() succeeds. If copying the generated cookie back to user space
fails after that point, the error path must not free those resources
again before dropping the MR reference.
Remove the duplicate unpin/free from the put_user() failure branch so
that MR teardown is handled only through the existing final cleanup
path. |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: atmel-aes - Fix 3-page memory leak in atmel_aes_buff_cleanup
atmel_aes_buff_init() allocates 4 pages using __get_free_pages() with
ATMEL_AES_BUFFER_ORDER, but atmel_aes_buff_cleanup() frees only the
first page using free_page(), leaking the remaining 3 pages. Use
free_pages() with ATMEL_AES_BUFFER_ORDER to fix the memory leak. |
| In the Linux kernel, the following vulnerability has been resolved:
cpufreq: governor: fix double free in cpufreq_dbs_governor_init() error path
When kobject_init_and_add() fails, cpufreq_dbs_governor_init() calls
kobject_put(&dbs_data->attr_set.kobj).
The kobject release callback cpufreq_dbs_data_release() calls
gov->exit(dbs_data) and kfree(dbs_data), but the current error path
then calls gov->exit(dbs_data) and kfree(dbs_data) again, causing a
double free.
Keep the direct kfree(dbs_data) for the gov->init() failure path, but
after kobject_init_and_add() has been called, let kobject_put() handle
the cleanup through cpufreq_dbs_data_release(). |
| In the Linux kernel, the following vulnerability has been resolved:
mm/kasan: fix double free for kasan pXds
kasan_free_pxd() assumes the page table is always struct page aligned.
But that's not always the case for all architectures. E.g. In case of
powerpc with 64K pagesize, PUD table (of size 4096) comes from slab cache
named pgtable-2^9. Hence instead of page_to_virt(pxd_page()) let's just
directly pass the start of the pxd table which is passed as the 1st
argument.
This fixes the below double free kasan issue seen with PMEM:
radix-mmu: Mapped 0x0000047d10000000-0x0000047f90000000 with 2.00 MiB pages
==================================================================
BUG: KASAN: double-free in kasan_remove_zero_shadow+0x9c4/0xa20
Free of addr c0000003c38e0000 by task ndctl/2164
CPU: 34 UID: 0 PID: 2164 Comm: ndctl Not tainted 6.19.0-rc1-00048-gea1013c15392 #157 VOLUNTARY
Hardware name: IBM,9080-HEX POWER10 (architected) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_012) hv:phyp pSeries
Call Trace:
dump_stack_lvl+0x88/0xc4 (unreliable)
print_report+0x214/0x63c
kasan_report_invalid_free+0xe4/0x110
check_slab_allocation+0x100/0x150
kmem_cache_free+0x128/0x6e0
kasan_remove_zero_shadow+0x9c4/0xa20
memunmap_pages+0x2b8/0x5c0
devm_action_release+0x54/0x70
release_nodes+0xc8/0x1a0
devres_release_all+0xe0/0x140
device_unbind_cleanup+0x30/0x120
device_release_driver_internal+0x3e4/0x450
unbind_store+0xfc/0x110
drv_attr_store+0x78/0xb0
sysfs_kf_write+0x114/0x140
kernfs_fop_write_iter+0x264/0x3f0
vfs_write+0x3bc/0x7d0
ksys_write+0xa4/0x190
system_call_exception+0x190/0x480
system_call_vectored_common+0x15c/0x2ec
---- interrupt: 3000 at 0x7fff93b3d3f4
NIP: 00007fff93b3d3f4 LR: 00007fff93b3d3f4 CTR: 0000000000000000
REGS: c0000003f1b07e80 TRAP: 3000 Not tainted (6.19.0-rc1-00048-gea1013c15392)
MSR: 800000000280f033 <SF,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE> CR: 48888208 XER: 00000000
<...>
NIP [00007fff93b3d3f4] 0x7fff93b3d3f4
LR [00007fff93b3d3f4] 0x7fff93b3d3f4
---- interrupt: 3000
The buggy address belongs to the object at c0000003c38e0000
which belongs to the cache pgtable-2^9 of size 4096
The buggy address is located 0 bytes inside of
4096-byte region [c0000003c38e0000, c0000003c38e1000)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3c38c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:c0000003bfd63e01
flags: 0x63ffff800000040(head|node=6|zone=0|lastcpupid=0x7ffff)
page_type: f5(slab)
raw: 063ffff800000040 c000000140058980 5deadbeef0000122 0000000000000000
raw: 0000000000000000 0000000080200020 00000000f5000000 c0000003bfd63e01
head: 063ffff800000040 c000000140058980 5deadbeef0000122 0000000000000000
head: 0000000000000000 0000000080200020 00000000f5000000 c0000003bfd63e01
head: 063ffff800000002 c00c000000f0e301 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
[ 138.953636] [ T2164] Memory state around the buggy address:
[ 138.953643] [ T2164] c0000003c38dff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 138.953652] [ T2164] c0000003c38dff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 138.953661] [ T2164] >c0000003c38e0000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 138.953669] [ T2164] ^
[ 138.953675] [ T2164] c0000003c38e0080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 138.953684] [ T2164] c0000003c38e0100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 138.953692] [ T2164] ==================================================================
[ 138.953701] [ T2164] Disabling lock debugging due to kernel taint |
| In the Linux kernel, the following vulnerability has been resolved:
ice: Fix memory leak in ice_set_ringparam()
In ice_set_ringparam, tx_rings and xdp_rings are allocated before
rx_rings. If the allocation of rx_rings fails, the code jumps to
the done label leaking both tx_rings and xdp_rings. Furthermore, if
the setup of an individual Rx ring fails during the loop, the code jumps
to the free_tx label which releases tx_rings but leaks xdp_rings.
Fix this by introducing a free_xdp label and updating the error paths to
ensure both xdp_rings and tx_rings are properly freed if rx_rings
allocation or setup fails.
Compile tested only. Issue found using a prototype static analysis tool
and code review. |
| In the Linux kernel, the following vulnerability has been resolved:
xfrm: defensively unhash xfrm_state lists in __xfrm_state_delete
KASAN reproduces a slab-use-after-free in __xfrm_state_delete()'s
hlist_del_rcu calls under syzkaller load on linux-6.12.y stable
(reproduced on 6.12.47, also reachable via the same code path on
torvalds/master and on the ipsec tree). Nine unique signatures cluster
in the xfrm_state lifecycle, the load-bearing one being:
BUG: KASAN: slab-use-after-free in __hlist_del include/linux/list.h:990 [inline]
BUG: KASAN: slab-use-after-free in hlist_del_rcu include/linux/rculist.h:516 [inline]
BUG: KASAN: slab-use-after-free in __xfrm_state_delete net/xfrm/xfrm_state.c
Write of size 8 at addr ffff8881198bcb70 by task kworker/u8:9/435
Workqueue: netns cleanup_net
Call Trace:
__hlist_del / hlist_del_rcu
__xfrm_state_delete
xfrm_state_delete
xfrm_state_flush
xfrm_state_fini
ops_exit_list
cleanup_net
The other observed signatures hit the same slab object from
__xfrm_state_lookup, xfrm_alloc_spi, __xfrm_state_insert and an OOB
write variant of __xfrm_state_delete, all on the byseq/byspi
hash chains.
__xfrm_state_delete() guards its byseq and byspi unhashes with
value-based predicates:
if (x->km.seq)
hlist_del_rcu(&x->byseq);
if (x->id.spi)
hlist_del_rcu(&x->byspi);
while everywhere else in the file (e.g. state_cache, state_cache_input)
the safer hlist_unhashed() check is used. xfrm_alloc_spi() sets
x->id.spi = newspi inside xfrm_state_lock and then immediately inserts
into byspi, but a path that observes x->id.spi != 0 outside of
xfrm_state_lock can still skip-or-hit the byspi unhash inconsistently
with whether x is actually on the list. The same holds for x->km.seq
versus byseq, and the bydst/bysrc unhashes have no predicate at all,
so a second __xfrm_state_delete() on the same object writes through
LIST_POISON pprev.
The defensive change here:
- Use hlist_del_init_rcu() instead of hlist_del_rcu() on bydst,
bysrc, byseq and byspi so a second deletion is a no-op rather
than a write through LIST_POISON pprev. The byseq/byspi nodes
are already initialised in xfrm_state_alloc().
- Test hlist_unhashed() rather than the value predicate for
byseq/byspi, so the unhash decision tracks list state rather than
mutable scalar fields.
Empirical verification: applied this patch on top of v6.12.47, rebuilt,
and re-ran the same syzkaller harness for 1h16m on a previously-crashy
configuration that produced ~100 hits each of slab-use-after-free
Read in xfrm_alloc_spi / Read in __xfrm_state_lookup / Write in
__xfrm_state_delete. After the patch, 7.1M execs across 32 VMs at
~1550 exec/sec produced zero xfrm_state UAF/OOB hits. /proc/slabinfo
confirms the xfrm_state slab is actively allocated and freed during
the run (~143 KiB resident), so the fuzzer is still exercising those
code paths -- they just no longer crash.
Reproduction:
- Linux 6.12.47 x86_64 + KASAN_GENERIC + KASAN_INLINE + KCOV
- syzkaller @ 746545b8b1e4c3a128db8652b340d3df90ce61db
- 32 QEMU/KVM VMs x 2 vCPU on AWS c5.metal bare metal
- 9 unique signatures collected in ~9h, all within xfrm_state
lifecycle |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: ccp - Fix a crash due to incorrect cleanup usage of kfree
Annotating a local pointer variable, which will be assigned with the
kmalloc-family functions, with the `__cleanup(kfree)` attribute will
make the address of the local variable, rather than the address returned
by kmalloc, passed to kfree directly and lead to a crash due to invalid
deallocation of stack address. According to other places in the repo,
the correct usage should be `__free(kfree)`. The code coincidentally
compiled because the parameter type `void *` of kfree is compatible with
the desired type `struct { ... } **`. |
| A weakness has been identified in ulisesbocchio jasypt-spring-boot up to 3.0.5/4.0.4. Affected by this vulnerability is the function getSecretKeySaltGenerator of the file jasypt-spring-boot/src/main/java/com/ulisesbocchio/jasyptspringboot/encryptor/SimpleGCMConfig.java of the component Password Hash Handler. Executing a manipulation can lead to use of a one-way hash with a predictable salt. The attack can be launched remotely. The attack requires a high level of complexity. The exploitation appears to be difficult. The exploit has been made available to the public and could be used for attacks. The project was informed of the problem early through an issue report but has not responded yet. |
| An issue was discovered in drivers/accessibility/speakup/spk_ttyio.c in the Linux kernel through 5.9.9. Local attackers on systems with the speakup driver could cause a local denial of service attack, aka CID-d41227544427. This occurs because of an invalid free when the line discipline is used more than once. |
| In the Linux kernel, the following vulnerability has been resolved:
powerpc/xive: fix kmemleak caused by incorrect chip_data lookup
The kmemleak reports the following memory leak:
Unreferenced object 0xc0000002a7fbc640 (size 64):
comm "kworker/8:1", pid 540, jiffies 4294937872
hex dump (first 32 bytes):
01 00 00 00 00 00 00 00 00 00 09 04 00 04 00 00 ................
00 00 a7 81 00 00 0a c0 00 00 08 04 00 04 00 00 ................
backtrace (crc 177d48f6):
__kmalloc_cache_noprof+0x520/0x730
xive_irq_alloc_data.constprop.0+0x40/0xe0
xive_irq_domain_alloc+0xd0/0x1b0
irq_domain_alloc_irqs_parent+0x44/0x6c
pseries_irq_domain_alloc+0x1cc/0x354
irq_domain_alloc_irqs_parent+0x44/0x6c
msi_domain_alloc+0xb0/0x220
irq_domain_alloc_irqs_locked+0x138/0x4d0
__irq_domain_alloc_irqs+0x8c/0xfc
__msi_domain_alloc_irqs+0x214/0x4d8
msi_domain_alloc_irqs_all_locked+0x70/0xf8
pci_msi_setup_msi_irqs+0x60/0x78
__pci_enable_msix_range+0x54c/0x98c
pci_alloc_irq_vectors_affinity+0x16c/0x1d4
nvme_pci_enable+0xac/0x9c0 [nvme]
nvme_probe+0x340/0x764 [nvme]
This occurs when allocating MSI-X vectors for an NVMe device. During
allocation the XIVE code creates a struct xive_irq_data and stores it
in irq_data->chip_data.
When the MSI-X irqdomain is later freed, xive_irq_free_data() is
responsible for retrieving this structure and freeing it. However,
after commit cc0cc23babc9 ("powerpc/xive: Untangle xive from child
interrupt controller drivers"), xive_irq_free_data() retrieves the
chip_data using irq_get_chip_data(), which looks up the data through
the child domain.
This is incorrect because the XIVE-specific irq data is associated with
the XIVE (parent) domain. As a result the lookup fails and the allocated
struct xive_irq_data is never freed, leading to the kmemleak report
shown above.
Fix this by retrieving the irq_data from the correct domain using
irq_domain_get_irq_data() and then accessing the chip_data via
irq_data_get_irq_chip_data(). |
| In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: fix ntfs_mount_options leak in ntfs_fill_super()
In ntfs_fill_super(), the fc->fs_private pointer is set to NULL without
first freeing the memory it points to. This causes the subsequent call to
ntfs_fs_free() to skip freeing the ntfs_mount_options structure.
This results in a kmemleak report:
unreferenced object 0xff1100015378b800 (size 32):
comm "mount", pid 582, jiffies 4294890685
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 ed ff ed ff 00 04 00 00 ................
backtrace (crc ed541d8c):
__kmalloc_cache_noprof+0x424/0x5a0
__ntfs_init_fs_context+0x47/0x590
alloc_fs_context+0x5d8/0x960
__x64_sys_fsopen+0xb1/0x190
do_syscall_64+0x50/0x1f0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
This issue can be reproduced using the following commands:
fallocate -l 100M test.file
mount test.file /tmp/test
Since sbi->options is duplicated from fc->fs_private and does not
directly use the memory allocated for fs_private, it is unnecessary to
set fc->fs_private to NULL.
Additionally, this patch simplifies the code by utilizing the helper
function put_mount_options() instead of open-coding the cleanup logic. |
| A CWE-760: Use of a One-Way Hash with a Predictable Salt vulnerability exists in Modicon M221 (all references, all versions), that could allow an attacker to pre-compute the hash value using dictionary attack technique such as rainbow tables, effectively disabling the protection that an unpredictable salt would provide. |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: nx - fix bounce buffer leaks in nx842_crypto_{alloc,free}_ctx
The bounce buffers are allocated with __get_free_pages() using
BOUNCE_BUFFER_ORDER (order 2 = 4 pages), but both the allocation error
path and nx842_crypto_free_ctx() release the buffers with free_page().
Use free_pages() with the matching order instead. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: Use kvfree instead of kfree in amdgpu_gmc_get_nps_memranges()
amdgpu_discovery_get_nps_info() internally allocates memory for ranges
using kvcalloc(), which may use vmalloc() for large allocation. Using
kfree() to release vmalloc memory will lead to a memory corruption.
Use kvfree() to safely handle both kmalloc and vmalloc allocations.
Compile tested only. Issue found using a prototype static analysis tool
and code review. |
| In the Linux kernel, the following vulnerability has been resolved:
md/md-llbitmap: raise barrier before state machine transition
Move the barrier raise operation before calling llbitmap_state_machine()
in both llbitmap_start_write() and llbitmap_start_discard(). This
ensures the barrier is in place before any state transitions occur,
preventing potential race conditions where the state machine could
complete before the barrier is properly raised. |
| In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: prevent infinite loops caused by the next valid being the same
When processing valid within the range [valid : pos), if valid cannot
be retrieved correctly, for example, if the retrieved valid value is
always the same, this can trigger a potential infinite loop, similar
to the hung problem reported by syzbot [1].
Adding a check for the valid value within the loop body, and terminating
the loop and returning -EINVAL if the value is the same as the current
value, can prevent this.
[1]
INFO: task syz.4.21:6056 blocked for more than 143 seconds.
Call Trace:
rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244
inode_lock include/linux/fs.h:1027 [inline]
ntfs_file_write_iter+0xe6/0x870 fs/ntfs3/file.c:1284 |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: target: Fix recursive locking in __configfs_open_file()
In flush_write_buffer, &p->frag_sem is acquired and then the loaded store
function is called, which, here, is target_core_item_dbroot_store(). This
function called filp_open(), following which these functions were called
(in reverse order), according to the call trace:
down_read
__configfs_open_file
do_dentry_open
vfs_open
do_open
path_openat
do_filp_open
file_open_name
filp_open
target_core_item_dbroot_store
flush_write_buffer
configfs_write_iter
target_core_item_dbroot_store() tries to validate the new file path by
trying to open the file path provided to it; however, in this case, the bug
report shows:
db_root: not a directory: /sys/kernel/config/target/dbroot
indicating that the same configfs file was tried to be opened, on which it
is currently working on. Thus, it is trying to acquire frag_sem semaphore
of the same file of which it already holds the semaphore obtained in
flush_write_buffer(), leading to acquiring the semaphore in a nested manner
and a possibility of recursive locking.
Fix this by modifying target_core_item_dbroot_store() to use kern_path()
instead of filp_open() to avoid opening the file using filesystem-specific
function __configfs_open_file(), and further modifying it to make this fix
compatible. |
