| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
drm/msm/disp/dpu1: set vbif hw config to NULL to avoid use after memory free during pm runtime resume
BUG: Unable to handle kernel paging request at virtual address 006b6b6b6b6b6be3
Call trace:
dpu_vbif_init_memtypes+0x40/0xb8
dpu_runtime_resume+0xcc/0x1c0
pm_generic_runtime_resume+0x30/0x44
__genpd_runtime_resume+0x68/0x7c
genpd_runtime_resume+0x134/0x258
__rpm_callback+0x98/0x138
rpm_callback+0x30/0x88
rpm_resume+0x36c/0x49c
__pm_runtime_resume+0x80/0xb0
dpu_core_irq_uninstall+0x30/0xb0
dpu_irq_uninstall+0x18/0x24
msm_drm_uninit+0xd8/0x16c
Patchwork: https://patchwork.freedesktop.org/patch/483255/
[DB: fixed Fixes tag] |
| In the Linux kernel, the following vulnerability has been resolved:
mt76: fix tx status related use-after-free race on station removal
There is a small race window where ongoing tx activity can lead to a skb
getting added to the status tracking idr after that idr has already been
cleaned up, which will keep the wcid linked in the status poll list.
Fix this by only adding status skbs if the wcid pointer is still assigned
in dev->wcid, which gets cleared early by mt76_sta_pre_rcu_remove |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: btmtksdio: fix use-after-free at btmtksdio_recv_event
We should not access skb buffer data anymore after hci_recv_frame was
called.
[ 39.634809] BUG: KASAN: use-after-free in btmtksdio_recv_event+0x1b0
[ 39.634855] Read of size 1 at addr ffffff80cf28a60d by task kworker
[ 39.634962] Call trace:
[ 39.634974] dump_backtrace+0x0/0x3b8
[ 39.634999] show_stack+0x20/0x2c
[ 39.635016] dump_stack_lvl+0x60/0x78
[ 39.635040] print_address_description+0x70/0x2f0
[ 39.635062] kasan_report+0x154/0x194
[ 39.635079] __asan_report_load1_noabort+0x44/0x50
[ 39.635099] btmtksdio_recv_event+0x1b0/0x1c4
[ 39.635129] btmtksdio_txrx_work+0x6cc/0xac4
[ 39.635157] process_one_work+0x560/0xc5c
[ 39.635177] worker_thread+0x7ec/0xcc0
[ 39.635195] kthread+0x2d0/0x3d0
[ 39.635215] ret_from_fork+0x10/0x20
[ 39.635247] Allocated by task 0:
[ 39.635260] (stack is not available)
[ 39.635281] Freed by task 2392:
[ 39.635295] kasan_save_stack+0x38/0x68
[ 39.635319] kasan_set_track+0x28/0x3c
[ 39.635338] kasan_set_free_info+0x28/0x4c
[ 39.635357] ____kasan_slab_free+0x104/0x150
[ 39.635374] __kasan_slab_free+0x18/0x28
[ 39.635391] slab_free_freelist_hook+0x114/0x248
[ 39.635410] kfree+0xf8/0x2b4
[ 39.635427] skb_free_head+0x58/0x98
[ 39.635447] skb_release_data+0x2f4/0x410
[ 39.635464] skb_release_all+0x50/0x60
[ 39.635481] kfree_skb+0xc8/0x25c
[ 39.635498] hci_event_packet+0x894/0xca4 [bluetooth]
[ 39.635721] hci_rx_work+0x1c8/0x68c [bluetooth]
[ 39.635925] process_one_work+0x560/0xc5c
[ 39.635951] worker_thread+0x7ec/0xcc0
[ 39.635970] kthread+0x2d0/0x3d0
[ 39.635990] ret_from_fork+0x10/0x20
[ 39.636021] The buggy address belongs to the object at ffffff80cf28a600
which belongs to the cache kmalloc-512 of size 512
[ 39.636039] The buggy address is located 13 bytes inside of
512-byte region [ffffff80cf28a600, ffffff80cf28a800) |
| In the Linux kernel, the following vulnerability has been resolved:
erofs: fix buffer copy overflow of ztailpacking feature
I got some KASAN report as below:
[ 46.959738] ==================================================================
[ 46.960430] BUG: KASAN: use-after-free in z_erofs_shifted_transform+0x2bd/0x370
[ 46.960430] Read of size 4074 at addr ffff8880300c2f8e by task fssum/188
...
[ 46.960430] Call Trace:
[ 46.960430] <TASK>
[ 46.960430] dump_stack_lvl+0x41/0x5e
[ 46.960430] print_report.cold+0xb2/0x6b7
[ 46.960430] ? z_erofs_shifted_transform+0x2bd/0x370
[ 46.960430] kasan_report+0x8a/0x140
[ 46.960430] ? z_erofs_shifted_transform+0x2bd/0x370
[ 46.960430] kasan_check_range+0x14d/0x1d0
[ 46.960430] memcpy+0x20/0x60
[ 46.960430] z_erofs_shifted_transform+0x2bd/0x370
[ 46.960430] z_erofs_decompress_pcluster+0xaae/0x1080
The root cause is that the tail pcluster won't be a complete filesystem
block anymore. So if ztailpacking is used, the second part of an
uncompressed tail pcluster may not be ``rq->pageofs_out``. |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/arm-smmu-v3-sva: Fix mm use-after-free
We currently call arm64_mm_context_put() without holding a reference to
the mm, which can result in use-after-free. Call mmgrab()/mmdrop() to
ensure the mm only gets freed after we unpinned the ASID. |
| In the Linux kernel, the following vulnerability has been resolved:
video: fbdev: vesafb: Fix a use-after-free due early fb_info cleanup
Commit b3c9a924aab6 ("fbdev: vesafb: Cleanup fb_info in .fb_destroy rather
than .remove") fixed a use-after-free error due the vesafb driver freeing
the fb_info in the .remove handler instead of doing it in .fb_destroy.
This can happen if the .fb_destroy callback is executed after the .remove
callback, since the former tries to access a pointer freed by the latter.
But that change didn't take into account that another possible scenario is
that .fb_destroy is called before the .remove callback. For example, if no
process has the fbdev chardev opened by the time the driver is removed.
If that's the case, fb_info will be freed when unregister_framebuffer() is
called, making the fb_info pointer accessed in vesafb_remove() after that
to no longer be valid.
To prevent that, move the expression containing the info->par to happen
before the unregister_framebuffer() function call. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: fix use-after-free in chanctx code
In ieee80211_vif_use_reserved_context(), when we have an
old context and the new context's replace_state is set to
IEEE80211_CHANCTX_REPLACE_NONE, we free the old context
in ieee80211_vif_use_reserved_reassign(). Therefore, we
cannot check the old_ctx anymore, so we should set it to
NULL after this point.
However, since the new_ctx replace state is clearly not
IEEE80211_CHANCTX_REPLACES_OTHER, we're not going to do
anything else in this function and can just return to
avoid accessing the freed old_ctx. |
| In the Linux kernel, the following vulnerability has been resolved:
bfq: Update cgroup information before merging bio
When the process is migrated to a different cgroup (or in case of
writeback just starts submitting bios associated with a different
cgroup) bfq_merge_bio() can operate with stale cgroup information in
bic. Thus the bio can be merged to a request from a different cgroup or
it can result in merging of bfqqs for different cgroups or bfqqs of
already dead cgroups and causing possible use-after-free issues. Fix the
problem by updating cgroup information in bfq_merge_bio(). |
| In the Linux kernel, the following vulnerability has been resolved:
bfq: Make sure bfqg for which we are queueing requests is online
Bios queued into BFQ IO scheduler can be associated with a cgroup that
was already offlined. This may then cause insertion of this bfq_group
into a service tree. But this bfq_group will get freed as soon as last
bio associated with it is completed leading to use after free issues for
service tree users. Fix the problem by making sure we always operate on
online bfq_group. If the bfq_group associated with the bio is not
online, we pick the first online parent. |
| In the Linux kernel, the following vulnerability has been resolved:
ubi: ubi_create_volume: Fix use-after-free when volume creation failed
There is an use-after-free problem for 'eba_tbl' in ubi_create_volume()'s
error handling path:
ubi_eba_replace_table(vol, eba_tbl)
vol->eba_tbl = tbl
out_mapping:
ubi_eba_destroy_table(eba_tbl) // Free 'eba_tbl'
out_unlock:
put_device(&vol->dev)
vol_release
kfree(tbl->entries) // UAF
Fix it by removing redundant 'eba_tbl' releasing.
Fetch a reproducer in [Link]. |
| In the Linux kernel, the following vulnerability has been resolved:
driver: base: fix UAF when driver_attach failed
When driver_attach(drv); failed, the driver_private will be freed.
But it has been added to the bus, which caused a UAF.
To fix it, we need to delete it from the bus when failed. |
| In the Linux kernel, the following vulnerability has been resolved:
blk-mq: don't touch ->tagset in blk_mq_get_sq_hctx
blk_mq_run_hw_queues() could be run when there isn't queued request and
after queue is cleaned up, at that time tagset is freed, because tagset
lifetime is covered by driver, and often freed after blk_cleanup_queue()
returns.
So don't touch ->tagset for figuring out current default hctx by the mapping
built in request queue, so use-after-free on tagset can be avoided. Meantime
this way should be fast than retrieving mapping from tagset. |
| In the Linux kernel, the following vulnerability has been resolved:
NFSD: Fix potential use-after-free in nfsd_file_put()
nfsd_file_put_noref() can free @nf, so don't dereference @nf
immediately upon return from nfsd_file_put_noref(). |
| In the Linux kernel, the following vulnerability has been resolved:
mt76: fix use-after-free by removing a non-RCU wcid pointer
Fixes an issue caught by KASAN about use-after-free in mt76_txq_schedule
by protecting mtxq->wcid with rcu_lock between mt76_txq_schedule and
sta_info_[alloc, free].
[18853.876689] ==================================================================
[18853.876751] BUG: KASAN: use-after-free in mt76_txq_schedule+0x204/0xaf8 [mt76]
[18853.876773] Read of size 8 at addr ffffffaf989a2138 by task mt76-tx phy0/883
[18853.876786]
[18853.876810] CPU: 5 PID: 883 Comm: mt76-tx phy0 Not tainted 5.10.100-fix-510-56778d365941-kasan #5 0b01fbbcf41a530f52043508fec2e31a4215
[18853.876840] Call trace:
[18853.876861] dump_backtrace+0x0/0x3ec
[18853.876878] show_stack+0x20/0x2c
[18853.876899] dump_stack+0x11c/0x1ac
[18853.876918] print_address_description+0x74/0x514
[18853.876934] kasan_report+0x134/0x174
[18853.876948] __asan_report_load8_noabort+0x44/0x50
[18853.876976] mt76_txq_schedule+0x204/0xaf8 [mt76 074e03e4640e97fe7405ee1fab547b81c4fa45d2]
[18853.877002] mt76_txq_schedule_all+0x2c/0x48 [mt76 074e03e4640e97fe7405ee1fab547b81c4fa45d2]
[18853.877030] mt7921_tx_worker+0xa0/0x1cc [mt7921_common f0875ebac9d7b4754e1010549e7db50fbd90a047]
[18853.877054] __mt76_worker_fn+0x190/0x22c [mt76 074e03e4640e97fe7405ee1fab547b81c4fa45d2]
[18853.877071] kthread+0x2f8/0x3b8
[18853.877087] ret_from_fork+0x10/0x30
[18853.877098]
[18853.877112] Allocated by task 941:
[18853.877131] kasan_save_stack+0x38/0x68
[18853.877147] __kasan_kmalloc+0xd4/0xfc
[18853.877163] kasan_kmalloc+0x10/0x1c
[18853.877177] __kmalloc+0x264/0x3c4
[18853.877294] sta_info_alloc+0x460/0xf88 [mac80211]
[18853.877410] ieee80211_prep_connection+0x204/0x1ee0 [mac80211]
[18853.877523] ieee80211_mgd_auth+0x6c4/0xa4c [mac80211]
[18853.877635] ieee80211_auth+0x20/0x2c [mac80211]
[18853.877733] rdev_auth+0x7c/0x438 [cfg80211]
[18853.877826] cfg80211_mlme_auth+0x26c/0x390 [cfg80211]
[18853.877919] nl80211_authenticate+0x6d4/0x904 [cfg80211]
[18853.877938] genl_rcv_msg+0x748/0x93c
[18853.877954] netlink_rcv_skb+0x160/0x2a8
[18853.877969] genl_rcv+0x3c/0x54
[18853.877985] netlink_unicast_kernel+0x104/0x1ec
[18853.877999] netlink_unicast+0x178/0x268
[18853.878015] netlink_sendmsg+0x3cc/0x5f0
[18853.878030] sock_sendmsg+0xb4/0xd8
[18853.878043] ____sys_sendmsg+0x2f8/0x53c
[18853.878058] ___sys_sendmsg+0xe8/0x150
[18853.878071] __sys_sendmsg+0xc4/0x1f4
[18853.878087] __arm64_compat_sys_sendmsg+0x88/0x9c
[18853.878101] el0_svc_common+0x1b4/0x390
[18853.878115] do_el0_svc_compat+0x8c/0xdc
[18853.878131] el0_svc_compat+0x10/0x1c
[18853.878146] el0_sync_compat_handler+0xa8/0xcc
[18853.878161] el0_sync_compat+0x188/0x1c0
[18853.878171]
[18853.878183] Freed by task 10927:
[18853.878200] kasan_save_stack+0x38/0x68
[18853.878215] kasan_set_track+0x28/0x3c
[18853.878228] kasan_set_free_info+0x24/0x48
[18853.878244] __kasan_slab_free+0x11c/0x154
[18853.878259] kasan_slab_free+0x14/0x24
[18853.878273] slab_free_freelist_hook+0xac/0x1b0
[18853.878287] kfree+0x104/0x390
[18853.878402] sta_info_free+0x198/0x210 [mac80211]
[18853.878515] __sta_info_destroy_part2+0x230/0x2d4 [mac80211]
[18853.878628] __sta_info_flush+0x300/0x37c [mac80211]
[18853.878740] ieee80211_set_disassoc+0x2cc/0xa7c [mac80211]
[18853.878851] ieee80211_mgd_deauth+0x4a4/0x10a0 [mac80211]
[18853.878962] ieee80211_deauth+0x20/0x2c [mac80211]
[18853.879057] rdev_deauth+0x7c/0x438 [cfg80211]
[18853.879150] cfg80211_mlme_deauth+0x274/0x414 [cfg80211]
[18853.879243] cfg80211_mlme_down+0xe4/0x118 [cfg80211]
[18853.879335] cfg80211_disconnect+0x218/0x2d8 [cfg80211]
[18853.879427] __cfg80211_leave+0x17c/0x240 [cfg80211]
[18853.879519] cfg80211_leave+0x3c/0x58 [cfg80211]
[18853.879611] wiphy_suspend+0xdc/0x200 [cfg80211]
[18853.879628] dpm_run_callback+0x58/0x408
[18853.879642] __device_suspend+0x4cc/0x864
[18853.879658] async_suspend+0x34/0xf4
[18
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
tpm: fix reference counting for struct tpm_chip
The following sequence of operations results in a refcount warning:
1. Open device /dev/tpmrm.
2. Remove module tpm_tis_spi.
3. Write a TPM command to the file descriptor opened at step 1.
------------[ cut here ]------------
WARNING: CPU: 3 PID: 1161 at lib/refcount.c:25 kobject_get+0xa0/0xa4
refcount_t: addition on 0; use-after-free.
Modules linked in: tpm_tis_spi tpm_tis_core tpm mdio_bcm_unimac brcmfmac
sha256_generic libsha256 sha256_arm hci_uart btbcm bluetooth cfg80211 vc4
brcmutil ecdh_generic ecc snd_soc_core crc32_arm_ce libaes
raspberrypi_hwmon ac97_bus snd_pcm_dmaengine bcm2711_thermal snd_pcm
snd_timer genet snd phy_generic soundcore [last unloaded: spi_bcm2835]
CPU: 3 PID: 1161 Comm: hold_open Not tainted 5.10.0ls-main-dirty #2
Hardware name: BCM2711
[<c0410c3c>] (unwind_backtrace) from [<c040b580>] (show_stack+0x10/0x14)
[<c040b580>] (show_stack) from [<c1092174>] (dump_stack+0xc4/0xd8)
[<c1092174>] (dump_stack) from [<c0445a30>] (__warn+0x104/0x108)
[<c0445a30>] (__warn) from [<c0445aa8>] (warn_slowpath_fmt+0x74/0xb8)
[<c0445aa8>] (warn_slowpath_fmt) from [<c08435d0>] (kobject_get+0xa0/0xa4)
[<c08435d0>] (kobject_get) from [<bf0a715c>] (tpm_try_get_ops+0x14/0x54 [tpm])
[<bf0a715c>] (tpm_try_get_ops [tpm]) from [<bf0a7d6c>] (tpm_common_write+0x38/0x60 [tpm])
[<bf0a7d6c>] (tpm_common_write [tpm]) from [<c05a7ac0>] (vfs_write+0xc4/0x3c0)
[<c05a7ac0>] (vfs_write) from [<c05a7ee4>] (ksys_write+0x58/0xcc)
[<c05a7ee4>] (ksys_write) from [<c04001a0>] (ret_fast_syscall+0x0/0x4c)
Exception stack(0xc226bfa8 to 0xc226bff0)
bfa0: 00000000 000105b4 00000003 beafe664 00000014 00000000
bfc0: 00000000 000105b4 000103f8 00000004 00000000 00000000 b6f9c000 beafe684
bfe0: 0000006c beafe648 0001056c b6eb6944
---[ end trace d4b8409def9b8b1f ]---
The reason for this warning is the attempt to get the chip->dev reference
in tpm_common_write() although the reference counter is already zero.
Since commit 8979b02aaf1d ("tpm: Fix reference count to main device") the
extra reference used to prevent a premature zero counter is never taken,
because the required TPM_CHIP_FLAG_TPM2 flag is never set.
Fix this by moving the TPM 2 character device handling from
tpm_chip_alloc() to tpm_add_char_device() which is called at a later point
in time when the flag has been set in case of TPM2.
Commit fdc915f7f719 ("tpm: expose spaces via a device link /dev/tpmrm<n>")
already introduced function tpm_devs_release() to release the extra
reference but did not implement the required put on chip->devs that results
in the call of this function.
Fix this by putting chip->devs in tpm_chip_unregister().
Finally move the new implementation for the TPM 2 handling into a new
function to avoid multiple checks for the TPM_CHIP_FLAG_TPM2 flag in the
good case and error cases. |
| In the Linux kernel, the following vulnerability has been resolved:
can: m_can: m_can_tx_handler(): fix use after free of skb
can_put_echo_skb() will clone skb then free the skb. Move the
can_put_echo_skb() for the m_can version 3.0.x directly before the
start of the xmit in hardware, similar to the 3.1.x branch. |
| In the Linux kernel, the following vulnerability has been resolved:
dm: fix use-after-free in dm_cleanup_zoned_dev()
dm_cleanup_zoned_dev() uses queue, so it must be called
before blk_cleanup_disk() starts its killing:
blk_cleanup_disk->blk_cleanup_queue()->kobject_put()->blk_release_queue()->
->...RCU...->blk_free_queue_rcu()->kmem_cache_free()
Otherwise, RCU callback may be executed first and
dm_cleanup_zoned_dev() will touch free'd memory:
BUG: KASAN: use-after-free in dm_cleanup_zoned_dev+0x33/0xd0
Read of size 8 at addr ffff88805ac6e430 by task dmsetup/681
CPU: 4 PID: 681 Comm: dmsetup Not tainted 5.17.0-rc2+ #6
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x7d
print_address_description.constprop.0+0x1f/0x150
? dm_cleanup_zoned_dev+0x33/0xd0
kasan_report.cold+0x7f/0x11b
? dm_cleanup_zoned_dev+0x33/0xd0
dm_cleanup_zoned_dev+0x33/0xd0
__dm_destroy+0x26a/0x400
? dm_blk_ioctl+0x230/0x230
? up_write+0xd8/0x270
dev_remove+0x156/0x1d0
ctl_ioctl+0x269/0x530
? table_clear+0x140/0x140
? lock_release+0xb2/0x750
? remove_all+0x40/0x40
? rcu_read_lock_sched_held+0x12/0x70
? lock_downgrade+0x3c0/0x3c0
? rcu_read_lock_sched_held+0x12/0x70
dm_ctl_ioctl+0xa/0x10
__x64_sys_ioctl+0xb9/0xf0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fb6dfa95c27 |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: ccree - Fix use after free in cc_cipher_exit()
kfree_sensitive(ctx_p->user.key) will free the ctx_p->user.key. But
ctx_p->user.key is still used in the next line, which will lead to a
use after free.
We can call kfree_sensitive() after dev_dbg() to avoid the uaf. |
| In the Linux kernel, the following vulnerability has been resolved:
ath11k: free peer for station when disconnect from AP for QCA6390/WCN6855
Commit b4a0f54156ac ("ath11k: move peer delete after vdev stop of station
for QCA6390 and WCN6855") is to fix firmware crash by changing the WMI
command sequence, but actually skip all the peer delete operation, then
it lead commit 58595c9874c6 ("ath11k: Fixing dangling pointer issue upon
peer delete failure") not take effect, and then happened a use-after-free
warning from KASAN. because the peer->sta is not set to NULL and then used
later.
Change to only skip the WMI_PEER_DELETE_CMDID for QCA6390/WCN6855.
log of user-after-free:
[ 534.888665] BUG: KASAN: use-after-free in ath11k_dp_rx_update_peer_stats+0x912/0xc10 [ath11k]
[ 534.888696] Read of size 8 at addr ffff8881396bb1b8 by task rtcwake/2860
[ 534.888705] CPU: 4 PID: 2860 Comm: rtcwake Kdump: loaded Tainted: G W 5.15.0-wt-ath+ #523
[ 534.888712] Hardware name: Intel(R) Client Systems NUC8i7HVK/NUC8i7HVB, BIOS HNKBLi70.86A.0067.2021.0528.1339 05/28/2021
[ 534.888716] Call Trace:
[ 534.888720] <IRQ>
[ 534.888726] dump_stack_lvl+0x57/0x7d
[ 534.888736] print_address_description.constprop.0+0x1f/0x170
[ 534.888745] ? ath11k_dp_rx_update_peer_stats+0x912/0xc10 [ath11k]
[ 534.888771] kasan_report.cold+0x83/0xdf
[ 534.888783] ? ath11k_dp_rx_update_peer_stats+0x912/0xc10 [ath11k]
[ 534.888810] ath11k_dp_rx_update_peer_stats+0x912/0xc10 [ath11k]
[ 534.888840] ath11k_dp_rx_process_mon_status+0x529/0xa70 [ath11k]
[ 534.888874] ? ath11k_dp_rx_mon_status_bufs_replenish+0x3f0/0x3f0 [ath11k]
[ 534.888897] ? check_prev_add+0x20f0/0x20f0
[ 534.888922] ? __lock_acquire+0xb72/0x1870
[ 534.888937] ? find_held_lock+0x33/0x110
[ 534.888954] ath11k_dp_rx_process_mon_rings+0x297/0x520 [ath11k]
[ 534.888981] ? rcu_read_unlock+0x40/0x40
[ 534.888990] ? ath11k_dp_rx_pdev_alloc+0xd90/0xd90 [ath11k]
[ 534.889026] ath11k_dp_service_mon_ring+0x67/0xe0 [ath11k]
[ 534.889053] ? ath11k_dp_rx_process_mon_rings+0x520/0x520 [ath11k]
[ 534.889075] call_timer_fn+0x167/0x4a0
[ 534.889084] ? add_timer_on+0x3b0/0x3b0
[ 534.889103] ? lockdep_hardirqs_on_prepare.part.0+0x18c/0x370
[ 534.889117] __run_timers.part.0+0x539/0x8b0
[ 534.889123] ? ath11k_dp_rx_process_mon_rings+0x520/0x520 [ath11k]
[ 534.889157] ? call_timer_fn+0x4a0/0x4a0
[ 534.889164] ? mark_lock_irq+0x1c30/0x1c30
[ 534.889173] ? clockevents_program_event+0xdd/0x280
[ 534.889189] ? mark_held_locks+0xa5/0xe0
[ 534.889203] run_timer_softirq+0x97/0x180
[ 534.889213] __do_softirq+0x276/0x86a
[ 534.889230] __irq_exit_rcu+0x11c/0x180
[ 534.889238] irq_exit_rcu+0x5/0x20
[ 534.889244] sysvec_apic_timer_interrupt+0x8e/0xc0
[ 534.889251] </IRQ>
[ 534.889254] <TASK>
[ 534.889259] asm_sysvec_apic_timer_interrupt+0x12/0x20
[ 534.889265] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70
[ 534.889271] Code: 74 24 10 e8 ea c2 bf fd 48 89 ef e8 12 53 c0 fd 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 <e8> 13 a7 b5 fd 65 8b 05 cc d9 9c 5e 85 c0 74 0a 5b 5d c3 e8 a0 ee
[ 534.889276] RSP: 0018:ffffc90002e5f880 EFLAGS: 00000206
[ 534.889284] RAX: 0000000000000006 RBX: 0000000000000200 RCX: ffffffff9f256f10
[ 534.889289] RDX: 0000000000000000 RSI: ffffffffa1c6e420 RDI: 0000000000000001
[ 534.889293] RBP: ffff8881095e6200 R08: 0000000000000001 R09: ffffffffa40d2b8f
[ 534.889298] R10: fffffbfff481a571 R11: 0000000000000001 R12: ffff8881095e6e68
[ 534.889302] R13: ffffc90002e5f908 R14: 0000000000000246 R15: 0000000000000000
[ 534.889316] ? mark_lock+0xd0/0x14a0
[ 534.889332] klist_next+0x1d4/0x450
[ 534.889340] ? dpm_wait_for_subordinate+0x2d0/0x2d0
[ 534.889350] device_for_each_child+0xa8/0x140
[ 534.889360] ? device_remove_class_symlinks+0x1b0/0x1b0
[ 534.889370] ? __lock_release+0x4bd/0x9f0
[ 534.889378] ? dpm_suspend+0x26b/0x3f0
[ 534.889390] dpm_wait_for_subordinate+
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix UAF due to race between btf_try_get_module and load_module
While working on code to populate kfunc BTF ID sets for module BTF from
its initcall, I noticed that by the time the initcall is invoked, the
module BTF can already be seen by userspace (and the BPF verifier). The
existing btf_try_get_module calls try_module_get which only fails if
mod->state == MODULE_STATE_GOING, i.e. it can increment module reference
when module initcall is happening in parallel.
Currently, BTF parsing happens from MODULE_STATE_COMING notifier
callback. At this point, the module initcalls have not been invoked.
The notifier callback parses and prepares the module BTF, allocates an
ID, which publishes it to userspace, and then adds it to the btf_modules
list allowing the kernel to invoke btf_try_get_module for the BTF.
However, at this point, the module has not been fully initialized (i.e.
its initcalls have not finished). The code in module.c can still fail
and free the module, without caring for other users. However, nothing
stops btf_try_get_module from succeeding between the state transition
from MODULE_STATE_COMING to MODULE_STATE_LIVE.
This leads to a use-after-free issue when BPF program loads
successfully in the state transition, load_module's do_init_module call
fails and frees the module, and BPF program fd on close calls module_put
for the freed module. Future patch has test case to verify we don't
regress in this area in future.
There are multiple points after prepare_coming_module (in load_module)
where failure can occur and module loading can return error. We
illustrate and test for the race using the last point where it can
practically occur (in module __init function).
An illustration of the race:
CPU 0 CPU 1
load_module
notifier_call(MODULE_STATE_COMING)
btf_parse_module
btf_alloc_id // Published to userspace
list_add(&btf_mod->list, btf_modules)
mod->init(...)
... ^
bpf_check |
check_pseudo_btf_id |
btf_try_get_module |
returns true | ...
... | module __init in progress
return prog_fd | ...
... V
if (ret < 0)
free_module(mod)
...
close(prog_fd)
...
bpf_prog_free_deferred
module_put(used_btf.mod) // use-after-free
We fix this issue by setting a flag BTF_MODULE_F_LIVE, from the notifier
callback when MODULE_STATE_LIVE state is reached for the module, so that
we return NULL from btf_try_get_module for modules that are not fully
formed. Since try_module_get already checks that module is not in
MODULE_STATE_GOING state, and that is the only transition a live module
can make before being removed from btf_modules list, this is enough to
close the race and prevent the bug.
A later selftest patch crafts the race condition artifically to verify
that it has been fixed, and that verifier fails to load program (with
ENXIO).
Lastly, a couple of comments:
1. Even if this race didn't exist, it seems more appropriate to only
access resources (ksyms and kfuncs) of a fully formed module which
has been initialized completely.
2. This patch was born out of need for synchronization against module
initcall for the next patch, so it is needed for correctness even
without the aforementioned race condition. The BTF resources
initialized by module initcall are set up once and then only looked
up, so just waiting until the initcall has finished ensures correct
behavior. |
