| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/rxe: Fix NULL-ptr-deref in rxe_qp_do_cleanup() when socket create failed
There is a null-ptr-deref when mount.cifs over rdma:
BUG: KASAN: null-ptr-deref in rxe_qp_do_cleanup+0x2f3/0x360 [rdma_rxe]
Read of size 8 at addr 0000000000000018 by task mount.cifs/3046
CPU: 2 PID: 3046 Comm: mount.cifs Not tainted 6.1.0-rc5+ #62
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc3
Call Trace:
<TASK>
dump_stack_lvl+0x34/0x44
kasan_report+0xad/0x130
rxe_qp_do_cleanup+0x2f3/0x360 [rdma_rxe]
execute_in_process_context+0x25/0x90
__rxe_cleanup+0x101/0x1d0 [rdma_rxe]
rxe_create_qp+0x16a/0x180 [rdma_rxe]
create_qp.part.0+0x27d/0x340
ib_create_qp_kernel+0x73/0x160
rdma_create_qp+0x100/0x230
_smbd_get_connection+0x752/0x20f0
smbd_get_connection+0x21/0x40
cifs_get_tcp_session+0x8ef/0xda0
mount_get_conns+0x60/0x750
cifs_mount+0x103/0xd00
cifs_smb3_do_mount+0x1dd/0xcb0
smb3_get_tree+0x1d5/0x300
vfs_get_tree+0x41/0xf0
path_mount+0x9b3/0xdd0
__x64_sys_mount+0x190/0x1d0
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
The root cause of the issue is the socket create failed in
rxe_qp_init_req().
So move the reset rxe_qp_do_cleanup() after the NULL ptr check. |
| In the Linux kernel, the following vulnerability has been resolved:
exfat: use kvmalloc_array/kvfree instead of kmalloc_array/kfree
The call stack shown below is a scenario in the Linux 4.19 kernel.
Allocating memory failed where exfat fs use kmalloc_array due to
system memory fragmentation, while the u-disk was inserted without
recognition.
Devices such as u-disk using the exfat file system are pluggable and
may be insert into the system at any time.
However, long-term running systems cannot guarantee the continuity of
physical memory. Therefore, it's necessary to address this issue.
Binder:2632_6: page allocation failure: order:4,
mode:0x6040c0(GFP_KERNEL|__GFP_COMP), nodemask=(null)
Call trace:
[242178.097582] dump_backtrace+0x0/0x4
[242178.097589] dump_stack+0xf4/0x134
[242178.097598] warn_alloc+0xd8/0x144
[242178.097603] __alloc_pages_nodemask+0x1364/0x1384
[242178.097608] kmalloc_order+0x2c/0x510
[242178.097612] kmalloc_order_trace+0x40/0x16c
[242178.097618] __kmalloc+0x360/0x408
[242178.097624] load_alloc_bitmap+0x160/0x284
[242178.097628] exfat_fill_super+0xa3c/0xe7c
[242178.097635] mount_bdev+0x2e8/0x3a0
[242178.097638] exfat_fs_mount+0x40/0x50
[242178.097643] mount_fs+0x138/0x2e8
[242178.097649] vfs_kern_mount+0x90/0x270
[242178.097655] do_mount+0x798/0x173c
[242178.097659] ksys_mount+0x114/0x1ac
[242178.097665] __arm64_sys_mount+0x24/0x34
[242178.097671] el0_svc_common+0xb8/0x1b8
[242178.097676] el0_svc_handler+0x74/0x90
[242178.097681] el0_svc+0x8/0x340
By analyzing the exfat code,we found that continuous physical memory
is not required here,so kvmalloc_array is used can solve this problem. |
| In the Linux kernel, the following vulnerability has been resolved:
driver core: fix potential null-ptr-deref in device_add()
I got the following null-ptr-deref report while doing fault injection test:
BUG: kernel NULL pointer dereference, address: 0000000000000058
CPU: 2 PID: 278 Comm: 37-i2c-ds2482 Tainted: G B W N 6.1.0-rc3+
RIP: 0010:klist_put+0x2d/0xd0
Call Trace:
<TASK>
klist_remove+0xf1/0x1c0
device_release_driver_internal+0x196/0x210
bus_remove_device+0x1bd/0x240
device_add+0xd3d/0x1100
w1_add_master_device+0x476/0x490 [wire]
ds2482_probe+0x303/0x3e0 [ds2482]
This is how it happened:
w1_alloc_dev()
// The dev->driver is set to w1_master_driver.
memcpy(&dev->dev, device, sizeof(struct device));
device_add()
bus_add_device()
dpm_sysfs_add() // It fails, calls bus_remove_device.
// error path
bus_remove_device()
// The dev->driver is not null, but driver is not bound.
__device_release_driver()
klist_remove(&dev->p->knode_driver) <-- It causes null-ptr-deref.
// normal path
bus_probe_device() // It's not called yet.
device_bind_driver()
If dev->driver is set, in the error path after calling bus_add_device()
in device_add(), bus_remove_device() is called, then the device will be
detached from driver. But device_bind_driver() is not called yet, so it
causes null-ptr-deref while access the 'knode_driver'. To fix this, set
dev->driver to null in the error path before calling bus_remove_device(). |
| In the Linux kernel, the following vulnerability has been resolved:
cxl/pmem: Fix nvdimm registration races
A loop of the form:
while true; do modprobe cxl_pci; modprobe -r cxl_pci; done
...fails with the following crash signature:
BUG: kernel NULL pointer dereference, address: 0000000000000040
[..]
RIP: 0010:cxl_internal_send_cmd+0x5/0xb0 [cxl_core]
[..]
Call Trace:
<TASK>
cxl_pmem_ctl+0x121/0x240 [cxl_pmem]
nvdimm_get_config_data+0xd6/0x1a0 [libnvdimm]
nd_label_data_init+0x135/0x7e0 [libnvdimm]
nvdimm_probe+0xd6/0x1c0 [libnvdimm]
nvdimm_bus_probe+0x7a/0x1e0 [libnvdimm]
really_probe+0xde/0x380
__driver_probe_device+0x78/0x170
driver_probe_device+0x1f/0x90
__device_attach_driver+0x85/0x110
bus_for_each_drv+0x7d/0xc0
__device_attach+0xb4/0x1e0
bus_probe_device+0x9f/0xc0
device_add+0x445/0x9c0
nd_async_device_register+0xe/0x40 [libnvdimm]
async_run_entry_fn+0x30/0x130
...namely that the bottom half of async nvdimm device registration runs
after the CXL has already torn down the context that cxl_pmem_ctl()
needs. Unlike the ACPI NFIT case that benefits from launching multiple
nvdimm device registrations in parallel from those listed in the table,
CXL is already marked PROBE_PREFER_ASYNCHRONOUS. So provide for a
synchronous registration path to preclude this scenario. |
| A vulnerability was detected in beecue FastBee up to 2.1. Impacted is the function getRootElement of the file springboot/fastbee-server/sip-server/src/main/java/com/fastbee/sip/handler/req/ReqAbstractHandler.java of the component SIP Message Handler. The manipulation results in xml external entity reference. It is possible to launch the attack remotely. A high complexity level is associated with this attack. The exploitability is considered difficult. The project owner replied to the issue report: "Okay, we'll handle it as soon as possible." |
| A vulnerability was determined in newbee-mall-plus 2.0.0. This impacts the function Upload of the file src/main/java/ltd/newbee/mall/controller/common/UploadController.java of the component Product Information Edit Page. This manipulation of the argument File causes unrestricted upload. The attack may be initiated remotely. The exploit has been publicly disclosed and may be utilized. The vendor was contacted early about this disclosure but did not respond in any way. |
| In the Linux kernel, the following vulnerability has been resolved:
mtd: spi-nor: Fix shift-out-of-bounds in spi_nor_set_erase_type
spi_nor_set_erase_type() was used either to set or to mask out an erase
type. When we used it to mask out an erase type a shift-out-of-bounds
was hit:
UBSAN: shift-out-of-bounds in drivers/mtd/spi-nor/core.c:2237:24
shift exponent 4294967295 is too large for 32-bit type 'int'
The setting of the size_{shift, mask} and of the opcode are unnecessary
when the erase size is zero, as throughout the code just the erase size
is considered to determine whether an erase type is supported or not.
Setting the opcode to 0xFF was wrong too as nobody guarantees that 0xFF
is an unused opcode. Thus when masking out an erase type, just set the
erase size to zero. This will fix the shift-out-of-bounds.
[ta: refine changes, new commit message, fix compilation error] |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: iwlwifi: dvm: Fix memcpy: detected field-spanning write backtrace
A received TKIP key may be up to 32 bytes because it may contain
MIC rx/tx keys too. These are not used by iwl and copying these
over overflows the iwl_keyinfo.key field.
Add a check to not copy more data to iwl_keyinfo.key then will fit.
This fixes backtraces like this one:
memcpy: detected field-spanning write (size 32) of single field "sta_cmd.key.key" at drivers/net/wireless/intel/iwlwifi/dvm/sta.c:1103 (size 16)
WARNING: CPU: 1 PID: 946 at drivers/net/wireless/intel/iwlwifi/dvm/sta.c:1103 iwlagn_send_sta_key+0x375/0x390 [iwldvm]
<snip>
Hardware name: Dell Inc. Latitude E6430/0H3MT5, BIOS A21 05/08/2017
RIP: 0010:iwlagn_send_sta_key+0x375/0x390 [iwldvm]
<snip>
Call Trace:
<TASK>
iwl_set_dynamic_key+0x1f0/0x220 [iwldvm]
iwlagn_mac_set_key+0x1e4/0x280 [iwldvm]
drv_set_key+0xa4/0x1b0 [mac80211]
ieee80211_key_enable_hw_accel+0xa8/0x2d0 [mac80211]
ieee80211_key_replace+0x22d/0x8e0 [mac80211]
<snip> |
| In the Linux kernel, the following vulnerability has been resolved:
nfsd: move init of percpu reply_cache_stats counters back to nfsd_init_net
Commit f5f9d4a314da ("nfsd: move reply cache initialization into nfsd
startup") moved the initialization of the reply cache into nfsd startup,
but didn't account for the stats counters, which can be accessed before
nfsd is ever started. The result can be a NULL pointer dereference when
someone accesses /proc/fs/nfsd/reply_cache_stats while nfsd is still
shut down.
This is a regression and a user-triggerable oops in the right situation:
- non-x86_64 arch
- /proc/fs/nfsd is mounted in the namespace
- nfsd is not started in the namespace
- unprivileged user calls "cat /proc/fs/nfsd/reply_cache_stats"
Although this is easy to trigger on some arches (like aarch64), on
x86_64, calling this_cpu_ptr(NULL) evidently returns a pointer to the
fixed_percpu_data. That struct looks just enough like a newly
initialized percpu var to allow nfsd_reply_cache_stats_show to access
it without Oopsing.
Move the initialization of the per-net+per-cpu reply-cache counters
back into nfsd_init_net, while leaving the rest of the reply cache
allocations to be done at nfsd startup time.
Kudos to Eirik who did most of the legwork to track this down. |
| In the Linux kernel, the following vulnerability has been resolved:
clk: imx93: fix memory leak and missing unwind goto in imx93_clocks_probe
In function probe(), it returns directly without unregistered hws
when error occurs.
Fix this by adding 'goto unregister_hws;' on line 295 and
line 310.
Use devm_kzalloc() instead of kzalloc() to automatically
free the memory using devm_kfree() when error occurs.
Replace of_iomap() with devm_of_iomap() to automatically
handle the unused ioremap region and delete 'iounmap(anatop_base);'
in unregister_hws. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: mpi3mr: Fix missing mrioc->evtack_cmds initialization
Commit c1af985d27da ("scsi: mpi3mr: Add Event acknowledgment logic")
introduced an array mrioc->evtack_cmds but initialization of the array
elements was missed. They are just zero cleared. The function
mpi3mr_complete_evt_ack() refers host_tag field of the elements. Due to the
zero value of the host_tag field, the function calls clear_bit() for
mrico->evtack_cmds_bitmap with wrong bit index. This results in memory
access to invalid address and "BUG: KASAN: use-after-free". This BUG was
observed at eHBA-9600 firmware update to version 8.3.1.0. To fix it, add
the missing initialization of mrioc->evtack_cmds. |
| In the Linux kernel, the following vulnerability has been resolved:
net/net_failover: fix txq exceeding warning
The failover txq is inited as 16 queues.
when a packet is transmitted from the failover device firstly,
the failover device will select the queue which is returned from
the primary device if the primary device is UP and running.
If the primary device txq is bigger than the default 16,
it can lead to the following warning:
eth0 selects TX queue 18, but real number of TX queues is 16
The warning backtrace is:
[ 32.146376] CPU: 18 PID: 9134 Comm: chronyd Tainted: G E 6.2.8-1.el7.centos.x86_64 #1
[ 32.147175] Hardware name: Red Hat KVM, BIOS 1.10.2-3.el7_4.1 04/01/2014
[ 32.147730] Call Trace:
[ 32.147971] <TASK>
[ 32.148183] dump_stack_lvl+0x48/0x70
[ 32.148514] dump_stack+0x10/0x20
[ 32.148820] netdev_core_pick_tx+0xb1/0xe0
[ 32.149180] __dev_queue_xmit+0x529/0xcf0
[ 32.149533] ? __check_object_size.part.0+0x21c/0x2c0
[ 32.149967] ip_finish_output2+0x278/0x560
[ 32.150327] __ip_finish_output+0x1fe/0x2f0
[ 32.150690] ip_finish_output+0x2a/0xd0
[ 32.151032] ip_output+0x7a/0x110
[ 32.151337] ? __pfx_ip_finish_output+0x10/0x10
[ 32.151733] ip_local_out+0x5e/0x70
[ 32.152054] ip_send_skb+0x19/0x50
[ 32.152366] udp_send_skb.isra.0+0x163/0x3a0
[ 32.152736] udp_sendmsg+0xba8/0xec0
[ 32.153060] ? __folio_memcg_unlock+0x25/0x60
[ 32.153445] ? __pfx_ip_generic_getfrag+0x10/0x10
[ 32.153854] ? sock_has_perm+0x85/0xa0
[ 32.154190] inet_sendmsg+0x6d/0x80
[ 32.154508] ? inet_sendmsg+0x6d/0x80
[ 32.154838] sock_sendmsg+0x62/0x70
[ 32.155152] ____sys_sendmsg+0x134/0x290
[ 32.155499] ___sys_sendmsg+0x81/0xc0
[ 32.155828] ? _get_random_bytes.part.0+0x79/0x1a0
[ 32.156240] ? ip4_datagram_release_cb+0x5f/0x1e0
[ 32.156649] ? get_random_u16+0x69/0xf0
[ 32.156989] ? __fget_light+0xcf/0x110
[ 32.157326] __sys_sendmmsg+0xc4/0x210
[ 32.157657] ? __sys_connect+0xb7/0xe0
[ 32.157995] ? __audit_syscall_entry+0xce/0x140
[ 32.158388] ? syscall_trace_enter.isra.0+0x12c/0x1a0
[ 32.158820] __x64_sys_sendmmsg+0x24/0x30
[ 32.159171] do_syscall_64+0x38/0x90
[ 32.159493] entry_SYSCALL_64_after_hwframe+0x72/0xdc
Fix that by reducing txq number as the non-existent primary-dev does. |
| In the Linux kernel, the following vulnerability has been resolved:
net/smc: fix potential panic dues to unprotected smc_llc_srv_add_link()
There is a certain chance to trigger the following panic:
PID: 5900 TASK: ffff88c1c8af4100 CPU: 1 COMMAND: "kworker/1:48"
#0 [ffff9456c1cc79a0] machine_kexec at ffffffff870665b7
#1 [ffff9456c1cc79f0] __crash_kexec at ffffffff871b4c7a
#2 [ffff9456c1cc7ab0] crash_kexec at ffffffff871b5b60
#3 [ffff9456c1cc7ac0] oops_end at ffffffff87026ce7
#4 [ffff9456c1cc7ae0] page_fault_oops at ffffffff87075715
#5 [ffff9456c1cc7b58] exc_page_fault at ffffffff87ad0654
#6 [ffff9456c1cc7b80] asm_exc_page_fault at ffffffff87c00b62
[exception RIP: ib_alloc_mr+19]
RIP: ffffffffc0c9cce3 RSP: ffff9456c1cc7c38 RFLAGS: 00010202
RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000004
RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88c1ea281d00 R8: 000000020a34ffff R9: ffff88c1350bbb20
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000010 R14: ffff88c1ab040a50 R15: ffff88c1ea281d00
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
#7 [ffff9456c1cc7c60] smc_ib_get_memory_region at ffffffffc0aff6df [smc]
#8 [ffff9456c1cc7c88] smcr_buf_map_link at ffffffffc0b0278c [smc]
#9 [ffff9456c1cc7ce0] __smc_buf_create at ffffffffc0b03586 [smc]
The reason here is that when the server tries to create a second link,
smc_llc_srv_add_link() has no protection and may add a new link to
link group. This breaks the security environment protected by
llc_conf_mutex. |
| In the Linux kernel, the following vulnerability has been resolved:
mlx5: fix skb leak while fifo resync and push
During ptp resync operation SKBs were poped from the fifo but were never
freed neither by napi_consume nor by dev_kfree_skb_any. Add call to
napi_consume_skb to properly free SKBs.
Another leak was happening because mlx5e_skb_fifo_has_room() had an error
in the check. Comparing free running counters works well unless C promotes
the types to something wider than the counter. In this case counters are
u16 but the result of the substraction is promouted to int and it causes
wrong result (negative value) of the check when producer have already
overlapped but consumer haven't yet. Explicit cast to u16 fixes the issue. |
| In the Linux kernel, the following vulnerability has been resolved:
net: ethernet: mtk_eth_soc: fix possible NULL pointer dereference in mtk_hwlro_get_fdir_all()
rule_locs is allocated in ethtool_get_rxnfc and the size is determined by
rule_cnt from user space. So rule_cnt needs to be check before using
rule_locs to avoid NULL pointer dereference. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: ebtables: fix table blob use-after-free
We are not allowed to return an error at this point.
Looking at the code it looks like ret is always 0 at this
point, but its not.
t = find_table_lock(net, repl->name, &ret, &ebt_mutex);
... this can return a valid table, with ret != 0.
This bug causes update of table->private with the new
blob, but then frees the blob right away in the caller.
Syzbot report:
BUG: KASAN: vmalloc-out-of-bounds in __ebt_unregister_table+0xc00/0xcd0 net/bridge/netfilter/ebtables.c:1168
Read of size 4 at addr ffffc90005425000 by task kworker/u4:4/74
Workqueue: netns cleanup_net
Call Trace:
kasan_report+0xbf/0x1f0 mm/kasan/report.c:517
__ebt_unregister_table+0xc00/0xcd0 net/bridge/netfilter/ebtables.c:1168
ebt_unregister_table+0x35/0x40 net/bridge/netfilter/ebtables.c:1372
ops_exit_list+0xb0/0x170 net/core/net_namespace.c:169
cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:613
...
ip(6)tables appears to be ok (ret should be 0 at this point) but make
this more obvious. |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: avoid out of bounds access in decode_preauth_ctxt()
Confirm that the accessed pneg_ctxt->HashAlgorithms address sits within
the SMB request boundary; deassemble_neg_contexts() only checks that the
eight byte smb2_neg_context header + (client controlled) DataLength are
within the packet boundary, which is insufficient.
Checking for sizeof(struct smb2_preauth_neg_context) is overkill given
that the type currently assumes SMB311_SALT_SIZE bytes of trailing Salt. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: set page extent mapped after read_folio in relocate_one_page
One of the CI runs triggered the following panic
assertion failed: PagePrivate(page) && page->private, in fs/btrfs/subpage.c:229
------------[ cut here ]------------
kernel BUG at fs/btrfs/subpage.c:229!
Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
CPU: 0 PID: 923660 Comm: btrfs Not tainted 6.5.0-rc3+ #1
pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
pc : btrfs_subpage_assert+0xbc/0xf0
lr : btrfs_subpage_assert+0xbc/0xf0
sp : ffff800093213720
x29: ffff800093213720 x28: ffff8000932138b4 x27: 000000000c280000
x26: 00000001b5d00000 x25: 000000000c281000 x24: 000000000c281fff
x23: 0000000000001000 x22: 0000000000000000 x21: ffffff42b95bf880
x20: ffff42b9528e0000 x19: 0000000000001000 x18: ffffffffffffffff
x17: 667274622f736620 x16: 6e69202c65746176 x15: 0000000000000028
x14: 0000000000000003 x13: 00000000002672d7 x12: 0000000000000000
x11: ffffcd3f0ccd9204 x10: ffffcd3f0554ae50 x9 : ffffcd3f0379528c
x8 : ffff800093213428 x7 : 0000000000000000 x6 : ffffcd3f091771e8
x5 : ffff42b97f333948 x4 : 0000000000000000 x3 : 0000000000000000
x2 : 0000000000000000 x1 : ffff42b9556cde80 x0 : 000000000000004f
Call trace:
btrfs_subpage_assert+0xbc/0xf0
btrfs_subpage_set_dirty+0x38/0xa0
btrfs_page_set_dirty+0x58/0x88
relocate_one_page+0x204/0x5f0
relocate_file_extent_cluster+0x11c/0x180
relocate_data_extent+0xd0/0xf8
relocate_block_group+0x3d0/0x4e8
btrfs_relocate_block_group+0x2d8/0x490
btrfs_relocate_chunk+0x54/0x1a8
btrfs_balance+0x7f4/0x1150
btrfs_ioctl+0x10f0/0x20b8
__arm64_sys_ioctl+0x120/0x11d8
invoke_syscall.constprop.0+0x80/0xd8
do_el0_svc+0x6c/0x158
el0_svc+0x50/0x1b0
el0t_64_sync_handler+0x120/0x130
el0t_64_sync+0x194/0x198
Code: 91098021 b0007fa0 91346000 97e9c6d2 (d4210000)
This is the same problem outlined in 17b17fcd6d44 ("btrfs:
set_page_extent_mapped after read_folio in btrfs_cont_expand") , and the
fix is the same. I originally looked for the same pattern elsewhere in
our code, but mistakenly skipped over this code because I saw the page
cache readahead before we set_page_extent_mapped, not realizing that
this was only in the !page case, that we can still end up with a
!uptodate page and then do the btrfs_read_folio further down.
The fix here is the same as the above mentioned patch, move the
set_page_extent_mapped call to after the btrfs_read_folio() block to
make sure that we have the subpage blocksize stuff setup properly before
using the page. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: Add missing gfx11 MQD manager callbacks
mqd_stride function was introduced in commit 2f77b9a242a2
("drm/amdkfd: Update MQD management on multi XCC setup")
but not assigned for gfx11. Fixes a NULL dereference in debugfs. |
| In the Linux kernel, the following vulnerability has been resolved:
blk-cgroup: Fix NULL deref caused by blkg_policy_data being installed before init
blk-iocost sometimes causes the following crash:
BUG: kernel NULL pointer dereference, address: 00000000000000e0
...
RIP: 0010:_raw_spin_lock+0x17/0x30
Code: be 01 02 00 00 e8 79 38 39 ff 31 d2 89 d0 5d c3 0f 1f 00 0f 1f 44 00 00 55 48 89 e5 65 ff 05 48 d0 34 7e b9 01 00 00 00 31 c0 <f0> 0f b1 0f 75 02 5d c3 89 c6 e8 ea 04 00 00 5d c3 0f 1f 84 00 00
RSP: 0018:ffffc900023b3d40 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 00000000000000e0 RCX: 0000000000000001
RDX: ffffc900023b3d20 RSI: ffffc900023b3cf0 RDI: 00000000000000e0
RBP: ffffc900023b3d40 R08: ffffc900023b3c10 R09: 0000000000000003
R10: 0000000000000064 R11: 000000000000000a R12: ffff888102337000
R13: fffffffffffffff2 R14: ffff88810af408c8 R15: ffff8881070c3600
FS: 00007faaaf364fc0(0000) GS:ffff88842fdc0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000e0 CR3: 00000001097b1000 CR4: 0000000000350ea0
Call Trace:
<TASK>
ioc_weight_write+0x13d/0x410
cgroup_file_write+0x7a/0x130
kernfs_fop_write_iter+0xf5/0x170
vfs_write+0x298/0x370
ksys_write+0x5f/0xb0
__x64_sys_write+0x1b/0x20
do_syscall_64+0x3d/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
This happens because iocg->ioc is NULL. The field is initialized by
ioc_pd_init() and never cleared. The NULL deref is caused by
blkcg_activate_policy() installing blkg_policy_data before initializing it.
blkcg_activate_policy() was doing the following:
1. Allocate pd's for all existing blkg's and install them in blkg->pd[].
2. Initialize all pd's.
3. Online all pd's.
blkcg_activate_policy() only grabs the queue_lock and may release and
re-acquire the lock as allocation may need to sleep. ioc_weight_write()
grabs blkcg->lock and iterates all its blkg's. The two can race and if
ioc_weight_write() runs during #1 or between #1 and #2, it can encounter a
pd which is not initialized yet, leading to crash.
The crash can be reproduced with the following script:
#!/bin/bash
echo +io > /sys/fs/cgroup/cgroup.subtree_control
systemd-run --unit touch-sda --scope dd if=/dev/sda of=/dev/null bs=1M count=1 iflag=direct
echo 100 > /sys/fs/cgroup/system.slice/io.weight
bash -c "echo '8:0 enable=1' > /sys/fs/cgroup/io.cost.qos" &
sleep .2
echo 100 > /sys/fs/cgroup/system.slice/io.weight
with the following patch applied:
> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
> index fc49be622e05..38d671d5e10c 100644
> --- a/block/blk-cgroup.c
> +++ b/block/blk-cgroup.c
> @@ -1553,6 +1553,12 @@ int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol)
> pd->online = false;
> }
>
> + if (system_state == SYSTEM_RUNNING) {
> + spin_unlock_irq(&q->queue_lock);
> + ssleep(1);
> + spin_lock_irq(&q->queue_lock);
> + }
> +
> /* all allocated, init in the same order */
> if (pol->pd_init_fn)
> list_for_each_entry_reverse(blkg, &q->blkg_list, q_node)
I don't see a reason why all pd's should be allocated, initialized and
onlined together. The only ordering requirement is that parent blkgs to be
initialized and onlined before children, which is guaranteed from the
walking order. Let's fix the bug by allocating, initializing and onlining pd
for each blkg and holding blkcg->lock over initialization and onlining. This
ensures that an installed blkg is always fully initialized and onlined
removing the the race window. |
