OESA-2025-1081

The Linux Kernel, the operating system core itself.

Security Fix(es):

A race condition was found in the Linux kernel's net/bluetooth in {conn,adv}_{min,max}_interval_set() function. This can result in I2cap connection or broadcast abnormality issue, possibly leading to denial of service.

(CVE-2024-24858)

In the Linux kernel, the following vulnerability has been resolved:

sched/membarrier: reduce the ability to hammer on sys_membarrier

On some systems, sys_membarrier can be very expensive, causing overall slowdowns for everything. So put a lock on the path in order to serialize the accesses to prevent the ability for this to be called at too high of a frequency and saturate the machine.(CVE-2024-26602)

In the Linux kernel, the following vulnerability has been resolved:

hv_netvsc: Register VF in netvsc_probe if NET_DEVICE_REGISTER missed

If hv_netvsc driver is unloaded and reloaded, the NET_DEVICE_REGISTER handler cannot perform VF register successfully as the register call is received before netvsc_probe is finished. This is because we register register_netdevice_notifier() very early( even before vmbus_driver_register()). To fix this, we try to register each such matching VF( if it is visible as a netdevice) at the end of netvsc_probe.(CVE-2024-26820)

In the Linux kernel, the following vulnerability has been resolved:

geneve: make sure to pull inner header in geneve_rx()

syzbot triggered a bug in geneve_rx() [1]

Issue is similar to the one I fixed in commit 8d975c15c0cd ("ip6_tunnel: make sure to pull inner header in __ip6_tnl_rcv()")

We have to save skb->network_header in a temporary variable in order to be able to recompute the network_header pointer after a pskb_inet_may_pull() call.

pskb_inet_may_pull() makes sure the needed headers are in skb->head.

[1] BUG: KMSAN: uninit-value in IP_ECN_decapsulate include/net/inet_ecn.h:302 [inline] BUG: KMSAN: uninit-value in geneve_rx drivers/net/geneve.c:279 [inline] BUG: KMSAN: uninit-value in geneve_udp_encap_recv+0x36f9/0x3c10 drivers/net/geneve.c:391 IP_ECN_decapsulate include/net/inet_ecn.h:302 [inline] geneve_rx drivers/net/geneve.c:279 [inline] geneve_udp_encap_recv+0x36f9/0x3c10 drivers/net/geneve.c:391 udp_queue_rcv_one_skb+0x1d39/0x1f20 net/ipv4/udp.c:2108 udp_queue_rcv_skb+0x6ae/0x6e0 net/ipv4/udp.c:2186 udp_unicast_rcv_skb+0x184/0x4b0 net/ipv4/udp.c:2346 __udp4_lib_rcv+0x1c6b/0x3010 net/ipv4/udp.c:2422 udp_rcv+0x7d/0xa0 net/ipv4/udp.c:2604 ip_protocol_deliver_rcu+0x264/0x1300 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x2b8/0x440 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:314 [inline] ip_local_deliver+0x21f/0x490 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:461 [inline] ip_rcv_finish net/ipv4/ip_input.c:449 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] ip_rcv+0x46f/0x760 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core net/core/dev.c:5534 [inline] __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5648 process_backlog+0x480/0x8b0 net/core/dev.c:5976 __napi_poll+0xe3/0x980 net/core/dev.c:6576 napi_poll net/core/dev.c:6645 [inline] net_rx_action+0x8b8/0x1870 net/core/dev.c:6778 __do_softirq+0x1b7/0x7c5 kernel/softirq.c:553 do_softirq+0x9a/0xf0 kernel/softirq.c:454 __local_bh_enable_ip+0x9b/0xa0 kernel/softirq.c:381 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:820 [inline] __dev_queue_xmit+0x2768/0x51c0 net/core/dev.c:4378 dev_queue_xmit include/linux/netdevice.h:3171 [inline] packet_xmit+0x9c/0x6b0 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3081 [inline] packet_sendmsg+0x8aef/0x9f10 net/packet/af_packet.c:3113 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x735/0xa10 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0x125/0x1c0 net/socket.c:2199 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b

Uninit was created at: slab_post_alloc_hook mm/slub.c:3819 [inline] slab_alloc_node mm/slub.c:3860 [inline] kmem_cache_alloc_node+0x5cb/0xbc0 mm/slub.c:3903 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:560 __alloc_skb+0x352/0x790 net/core/skbuff.c:651 alloc_skb include/linux/skbuff.h:1296 [inline] alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6394 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2783 packet_alloc_skb net/packet/af_packet.c:2930 [inline] packet_snd net/packet/af_packet.c:3024 [inline] packet_sendmsg+0x70c2/0x9f10 net/packet/af_packet.c:3113 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x735/0xa10 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0x125/0x1c0 net/socket.c:2199 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b(CVE-2024-26857)

In the Linux kernel, the following vulnerability has been resolved:

nilfs2: fix failure to detect DAT corruption in btree and direct mappings

Patch series "nilfs2: fix kernel bug at submit_bh_wbc()".

This resolves a kernel BUG reported by syzbot. Since there are two flaws involved, I've made each one a separate patch.

The first patch alone resolves the syzbot-reported bug, but I think both fixes should be sent to stable, so I've tagged them as such.

This patch (of 2):

Syzbot has reported a kernel bug in submit_bh_wbc() when writing file data to a nilfs2 file system whose metadata is corrupted.

There are two flaws involved in this issue.

The first flaw is that when nilfs_get_block() locates a data block using btree or direct mapping, if the disk address translation routine nilfs_dat_translate() fails with internal code -ENOENT due to DAT metadata corruption, it can be passed back to nilfs_get_block(). This causes nilfs_get_block() to misidentify an existing block as non-existent, causing both data block lookup and insertion to fail inconsistently.

The second flaw is that nilfs_get_block() returns a successful status in this inconsistent state. This causes the caller __block_write_begin_int() or others to request a read even though the buffer is not mapped, resulting in a BUG_ON check for the BH_Mapped flag in submit_bh_wbc() failing.

This fixes the first issue by changing the return value to code -EINVAL when a conversion using DAT fails with code -ENOENT, avoiding the conflicting condition that leads to the kernel bug described above. Here, code -EINVAL indicates that metadata corruption was detected during the block lookup, which will be properly handled as a file system error and converted to -EIO when passing through the nilfs2 bmap layer.(CVE-2024-26956)

In the Linux kernel, the following vulnerability has been resolved:

clk: qcom: mmcc-apq8084: fix terminating of frequency table arrays

The frequency table arrays are supposed to be terminated with an empty element. Add such entry to the end of the arrays where it is missing in order to avoid possible out-of-bound access when the table is traversed by functions like qcom_find_freq() or qcom_find_freq_floor().

Only compile tested.(CVE-2024-26966)

In the Linux kernel, the following vulnerability has been resolved:

clk: qcom: gcc-ipq8074: fix terminating of frequency table arrays

The frequency table arrays are supposed to be terminated with an empty element. Add such entry to the end of the arrays where it is missing in order to avoid possible out-of-bound access when the table is traversed by functions like qcom_find_freq() or qcom_find_freq_floor().

Only compile tested.(CVE-2024-26969)

In the Linux kernel, the following vulnerability has been resolved:

crypto: qat - resolve race condition during AER recovery

During the PCI AER system's error recovery process, the kernel driver may encounter a race condition with freeing the reset_data structure's memory. If the device restart will take more than 10 seconds the function scheduling that restart will exit due to a timeout, and the reset_data structure will be freed. However, this data structure is used for completion notification after the restart is completed, which leads to a UAF bug.

This results in a KFENCE bug notice.

BUG: KFENCE: use-after-free read in adf_device_reset_worker+0x38/0xa0 [intel_qat] Use-after-free read at 0x00000000bc56fddf (in kfence-#142): adf_device_reset_worker+0x38/0xa0 [intel_qat] process_one_work+0x173/0x340

To resolve this race condition, the memory associated to the container of the work_struct is freed on the worker if the timeout expired, otherwise on the function that schedules the worker. The timeout detection can be done by checking if the caller is still waiting for completion or not by using completion_done() function.(CVE-2024-26974)

In the Linux kernel, the following vulnerability has been resolved:

nilfs2: fix OOB in nilfs_set_de_type

The size of the nilfs_type_by_mode array in the fs/nilfs2/dir.c file is defined as "S_IFMT >> S_SHIFT", but the nilfs_set_de_type() function, which uses this array, specifies the index to read from the array in the same way as "(mode & S_IFMT) >> S_SHIFT".

static void nilfs_set_de_type(struct nilfs_dir_entry *de, struct inode *inode) { umode_t mode = inode->i_mode;

de->file_type = nilfs_type_by_mode[(mode & S_IFMT)>>S_SHIFT]; // oob

}

However, when the index is determined this way, an out-of-bounds (OOB) error occurs by referring to an index that is 1 larger than the array size when the condition "mode & S_IFMT == S_IFMT" is satisfied. Therefore, a patch to resize the nilfs_type_by_mode array should be applied to prevent OOB errors.(CVE-2024-26981)

In the Linux kernel, the following vulnerability has been resolved:

comedi: vmk80xx: fix incomplete endpoint checking

While vmk80xx does have endpoint checking implemented, some things can fall through the cracks. Depending on the hardware model, URBs can have either bulk or interrupt type, and current version of vmk80xx_find_usb_endpoints() function does not take that fully into account. While this warning does not seem to be too harmful, at the very least it will crash systems with 'panic_on_warn' set on them.

Fix the issue found by Syzkaller [1] by somewhat simplifying the endpoint checking process with usb_find_common_endpoints() and ensuring that only expected endpoint types are present.

This patch has not been tested on real hardware.

[1] Syzkaller report: usb 1-1: BOGUS urb xfer, pipe 1 != type 3 WARNING: CPU: 0 PID: 781 at drivers/usb/core/urb.c:504 usb_submit_urb+0xc4e/0x18c0 drivers/usb/core/urb.c:503 ... Call Trace: <TASK> usb_start_wait_urb+0x113/0x520 drivers/usb/core/message.c:59 vmk80xx_reset_device drivers/comedi/drivers/vmk80xx.c:227 [inline] vmk80xx_auto_attach+0xa1c/0x1a40 drivers/comedi/drivers/vmk80xx.c:818 comedi_auto_config+0x238/0x380 drivers/comedi/drivers.c:1067 usb_probe_interface+0x5cd/0xb00 drivers/usb/core/driver.c:399 ...

Similar issue also found by Syzkaller:(CVE-2024-27001)

In the Linux kernel, the following vulnerability has been resolved:

media: atomisp: ssh_css: Fix a null-pointer dereference in load_video_binaries

The allocation failure of mycs->yuv_scaler_binary in load_video_binaries() is followed with a dereference of mycs->yuv_scaler_binary after the following call chain:

sh_css_pipe_load_binaries() |-> load_video_binaries(mycs->yuv_scaler_binary == NULL) | |-> sh_css_pipe_unload_binaries() |-> unload_video_binaries()

In unload_video_binaries(), it calls to ia_css_binary_unload with argument &pipe->pipe_settings.video.yuv_scaler_binary[i], which refers to the same memory slot as mycs->yuv_scaler_binary. Thus, a null-pointer dereference is triggered.(CVE-2024-38547)

In the Linux kernel, the following vulnerability has been resolved:

media: stk1160: fix bounds checking in stk1160_copy_video()

The subtract in this condition is reversed. The ->length is the length of the buffer. The ->bytesused is how many bytes we have copied thus far. When the condition is reversed that means the result of the subtraction is always negative but since it's unsigned then the result is a very high positive value. That means the overflow check is never true.

Additionally, the ->bytesused doesn't actually work for this purpose because we're not writing to "buf->mem + buf->bytesused". Instead, the math to calculate the destination where we are writing is a bit involved. You calculate the number of full lines already written, multiply by two, skip a line if necessary so that we start on an odd numbered line, and add the offset into the line.

To fix this buffer overflow, just take the actual destination where we are writing, if the offset is already out of bounds print an error and return. Otherwise, write up to buf->length bytes.(CVE-2024-38621)

In the Linux kernel, the following vulnerability has been resolved:

s390/sclp: Prevent release of buffer in I/O

When a task waiting for completion of a Store Data operation is interrupted, an attempt is made to halt this operation. If this attempt fails due to a hardware or firmware problem, there is a chance that the SCLP facility might store data into buffers referenced by the original operation at a later time.

Handle this situation by not releasing the referenced data buffers if the halt attempt fails. For current use cases, this might result in a leak of few pages of memory in case of a rare hardware/firmware malfunction.(CVE-2024-44969)

In the Linux kernel, the following vulnerability has been resolved:

dm cache: fix out-of-bounds access to the dirty bitset when resizing

dm-cache checks the dirty bits of the cache blocks to be dropped when shrinking the fast device, but an index bug in bitset iteration causes out-of-bounds access.

Reproduce steps:

1. create a cache device of 1024 cache blocks (128 bytes dirty bitset)

dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" dmsetup create cdata --table "0 131072 linear /dev/sdc 8192" dmsetup create corig --table "0 524288 linear /dev/sdc 262144" dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 oflag=direct dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta
/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0"

1. shrink the fast device to 512 cache blocks, triggering out-of-bounds access to the dirty bitset (offset 0x80)

dmsetup suspend cache dmsetup reload cdata --table "0 65536 linear /dev/sdc 8192" dmsetup resume cdata dmsetup resume cache

KASAN reports:

BUG: KASAN: vmalloc-out-of-bounds in cache_preresume+0x269/0x7b0 Read of size 8 at addr ffffc900000f3080 by task dmsetup/131

(...snip...) The buggy address belongs to the virtual mapping at [ffffc900000f3000, ffffc900000f5000) created by: cache_ctr+0x176a/0x35f0

(...snip...) Memory state around the buggy address: ffffc900000f2f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc900000f3000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffffc900000f3080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ ffffc900000f3100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc900000f3180: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8

Fix by making the index post-incremented.(CVE-2024-50279)

In the Linux kernel, the following vulnerability has been resolved:

drm/i915/hdcp: Add encoder check in hdcp2_get_capability

Add encoder check in intel_hdcp2_get_capability to avoid null pointer error.(CVE-2024-53050)

In the Linux kernel, the following vulnerability has been resolved:

RDMA/hns: Fix NULL pointer derefernce in hns_roce_map_mr_sg()

ib_map_mr_sg() allows ULPs to specify NULL as the sg_offset argument. The driver needs to check whether it is a NULL pointer before dereferencing it.(CVE-2024-53226)

In the Linux kernel, the following vulnerability has been resolved:

cachefiles: Fix NULL pointer dereference in object->file

At present, the object->file has the NULL pointer dereference problem in ondemand-mode. The root cause is that the allocated fd and object->file lifetime are inconsistent, and the user-space invocation to anon_fd uses object->file. Following is the process that triggers the issue:

  [write fd]				[umount]

cachefiles_ondemand_fd_write_iter fscache_cookie_state_machine cachefiles_withdraw_cookie if (!file) return -ENOBUFS cachefiles_clean_up_object cachefiles_unmark_inode_in_use fput(object->file) object->file = NULL // file NULL pointer dereference! __cachefiles_write(..., file, ...)

Fix this issue by add an additional reference count to the object->file before write/llseek, and decrement after it finished.(CVE-2024-56549)

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: fix Out-of-Bounds Write in ksmbd_vfs_stream_write

An offset from client could be a negative value, It could allows to write data outside the bounds of the allocated buffer. Note that this issue is coming when setting 'vfs objects = streams_xattr parameter' in ksmbd.conf..(CVE-2024-56626)

In the Linux kernel, the following vulnerability has been resolved:

net: hsr: avoid potential out-of-bound access in fill_frame_info()

syzbot is able to feed a packet with 14 bytes, pretending it is a vlan one.

Since fill_frame_info() is relying on skb->mac_len already, extend the check to cover this case.

BUG: KMSAN: uninit-value in fill_frame_info net/hsr/hsr_forward.c:709 [inline] BUG: KMSAN: uninit-value in hsr_forward_skb+0x9ee/0x3b10 net/hsr/hsr_forward.c:724 fill_frame_info net/hsr/hsr_forward.c:709 [inline] hsr_forward_skb+0x9ee/0x3b10 net/hsr/hsr_forward.c:724 hsr_dev_xmit+0x2f0/0x350 net/hsr/hsr_device.c:235 __netdev_start_xmit include/linux/netdevice.h:5002 [inline] netdev_start_xmit include/linux/netdevice.h:5011 [inline] xmit_one net/core/dev.c:3590 [inline] dev_hard_start_xmit+0x247/0xa20 net/core/dev.c:3606 __dev_queue_xmit+0x366a/0x57d0 net/core/dev.c:4434 dev_queue_xmit include/linux/netdevice.h:3168 [inline] packet_xmit+0x9c/0x6c0 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3146 [inline] packet_sendmsg+0x91ae/0xa6f0 net/packet/af_packet.c:3178 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg+0x30f/0x380 net/socket.c:726 __sys_sendto+0x594/0x750 net/socket.c:2197 __do_sys_sendto net/socket.c:2204 [inline] __se_sys_sendto net/socket.c:2200 [inline] __x64_sys_sendto+0x125/0x1d0 net/socket.c:2200 x64_sys_call+0x346a/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:45 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at: slab_post_alloc_hook mm/slub.c:4091 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4186 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:587 __alloc_skb+0x363/0x7b0 net/core/skbuff.c:678 alloc_skb include/linux/skbuff.h:1323 [inline] alloc_skb_with_frags+0xc8/0xd00 net/core/skbuff.c:6612 sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2881 packet_alloc_skb net/packet/af_packet.c:2995 [inline] packet_snd net/packet/af_packet.c:3089 [inline] packet_sendmsg+0x74c6/0xa6f0 net/packet/af_packet.c:3178 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg+0x30f/0x380 net/socket.c:726 __sys_sendto+0x594/0x750 net/socket.c:2197 __do_sys_sendto net/socket.c:2204 [inline] __se_sys_sendto net/socket.c:2200 [inline] __x64_sys_sendto+0x125/0x1d0 net/socket.c:2200 x64_sys_call+0x346a/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:45 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f(CVE-2024-56648)

In the Linux kernel, the following vulnerability has been resolved:

crypto: pcrypt - Call crypto layer directly when padata_do_parallel() return -EBUSY

Since commit 8f4f68e788c3 ("crypto: pcrypt - Fix hungtask for PADATA_RESET"), the pcrypt encryption and decryption operations return -EAGAIN when the CPU goes online or offline. In alg_test(), a WARN is generated when pcrypt_aead_decrypt() or pcrypt_aead_encrypt() returns -EAGAIN, the unnecessary panic will occur when panic_on_warn set 1. Fix this issue by calling crypto layer directly without parallelization in that case.(CVE-2024-56690)

In the Linux kernel, the following vulnerability has been resolved:

octeontx2-pf: handle otx2_mbox_get_rsp errors in otx2_ethtool.c

Add error pointer check after calling otx2_mbox_get_rsp().(CVE-2024-56728)

In the Linux kernel, the following vulnerability has been resolved:

btrfs: check folio mapping after unlock in relocate_one_folio()

When we call btrfs_read_folio() to bring a folio uptodate, we unlock the folio. The result of that is that a different thread can modify the mapping (like remove it with invalidate) before we call folio_lock(). This results in an invalid page and we need to try again.

In particular, if we are relocating concurrently with aborting a transaction, this can result in a crash like the following:

BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 0 P4D 0 Oops: 0000 [#1] SMP CPU: 76 PID: 1411631 Comm: kworker/u322:5 Workqueue: events_unbound btrfs_reclaim_bgs_work RIP: 0010:set_page_extent_mapped+0x20/0xb0 RSP: 0018:ffffc900516a7be8 EFLAGS: 00010246 RAX: ffffea009e851d08 RBX: ffffea009e0b1880 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffc900516a7b90 RDI: ffffea009e0b1880 RBP: 0000000003573000 R08: 0000000000000001 R09: ffff88c07fd2f3f0 R10: 0000000000000000 R11: 0000194754b575be R12: 0000000003572000 R13: 0000000003572fff R14: 0000000000100cca R15: 0000000005582fff FS: 0000000000000000(0000) GS:ffff88c07fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000407d00f002 CR4: 00000000007706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> ? __die+0x78/0xc0 ? page_fault_oops+0x2a8/0x3a0 ? __switch_to+0x133/0x530 ? wq_worker_running+0xa/0x40 ? exc_page_fault+0x63/0x130 ? asm_exc_page_fault+0x22/0x30 ? set_page_extent_mapped+0x20/0xb0 relocate_file_extent_cluster+0x1a7/0x940 relocate_data_extent+0xaf/0x120 relocate_block_group+0x20f/0x480 btrfs_relocate_block_group+0x152/0x320 btrfs_relocate_chunk+0x3d/0x120 btrfs_reclaim_bgs_work+0x2ae/0x4e0 process_scheduled_works+0x184/0x370 worker_thread+0xc6/0x3e0 ? blk_add_timer+0xb0/0xb0 kthread+0xae/0xe0 ? flush_tlb_kernel_range+0x90/0x90 ret_from_fork+0x2f/0x40 ? flush_tlb_kernel_range+0x90/0x90 ret_from_fork_asm+0x11/0x20 </TASK>

This occurs because cleanup_one_transaction() calls destroy_delalloc_inodes() which calls invalidate_inode_pages2() which takes the folio_lock before setting mapping to NULL. We fail to check this, and subsequently call set_extent_mapping(), which assumes that mapping != NULL (in fact it asserts that in debug mode)

Note that the "fixes" patch here is not the one that introduced the race (the very first iteration of this code from 2009) but a more recent change that made this particular crash happen in practice.(CVE-2024-56758)