The dm_get_from_kobject function in drivers/md/dm.c in the Linux kernel before 4.14.3 allow local users to cause a denial of service (BUG) by leveraging a race condition with __dm_destroy during creation and removal of DM devices.

In the Linux kernel before 4.15, fs/ocfs2/aops.c omits use of a semaphore and consequently has a race condition for access to the extent tree during read operations in DIRECT mode, which allows local users to cause a denial of service (BUG) by modifying a certain e_cpos field.

A race condition was discovered in get_old_root in fs/btrfs/ctree.c in the Linux kernel through 5.11.8. It allows attackers to cause a denial of service (BUG) because of a lack of locking on an extent buffer before a cloning operation, aka CID-dbcc7d57bffc.

Race condition in the ioctl_send_fib function in drivers/scsi/aacraid/commctrl.c in the Linux kernel through 4.7 allows local users to cause a denial of service (out-of-bounds access or system crash) by changing a certain size value, aka a "double fetch" vulnerability.

The snd_timer_interrupt function in sound/core/timer.c in the Linux kernel before 4.4.1 does not properly maintain a certain linked list, which allows local users to cause a denial of service (race condition and system crash) via a crafted ioctl call.

Race condition in the queue_delete function in sound/core/seq/seq_queue.c in the Linux kernel before 4.4.1 allows local users to cause a denial of service (use-after-free and system crash) by making an ioctl call at a certain time.

sound/core/timer.c in the Linux kernel before 4.4.1 uses an incorrect type of mutex, which allows local users to cause a denial of service (race condition, use-after-free, and system crash) via a crafted ioctl call.

Multiple race conditions in the ext4 filesystem implementation in the Linux kernel before 4.5 allow local users to cause a denial of service (disk corruption) by writing to a page that is associated with a different user's file after unsynchronized hole punching and page-fault handling.

sound/core/timer.c in the Linux kernel before 4.4.1 employs a locking approach that does not consider slave timer instances, which allows local users to cause a denial of service (race condition, use-after-free, and system crash) via a crafted ioctl call.

A pivot_root race condition in fs/namespace.c in the Linux kernel 4.4.x before 4.4.221, 4.9.x before 4.9.221, 4.14.x before 4.14.178, 4.19.x before 4.19.119, and 5.x before 5.3 allows local users to cause a denial of service (panic) by corrupting a mountpoint reference counter.

The fallocate implementation in the GFS2 filesystem in the Linux kernel before 3.2 relies on the page cache, which might allow local users to cause a denial of service by preallocating blocks in certain situations involving insufficient memory.

Multiple integer signedness errors in net/rose/af_rose.c in the Linux kernel before 2.6.36-rc5-next-20100923 allow local users to cause a denial of service (heap memory corruption) or possibly have unspecified other impact via a rose_getname function call, related to the rose_bind and rose_connect functions.

The inode double locking code in fs/ocfs2/file.c in the Linux kernel 2.6.30 before 2.6.30-rc3, 2.6.27 before 2.6.27.24, 2.6.29 before 2.6.29.4, and possibly other versions down to 2.6.19 allows local users to cause a denial of service (prevention of file creation and removal) via a series of splice system calls that trigger a deadlock between the generic_file_splice_write, splice_from_pipe, and ocfs2_file_splice_write functions.

IBM Db2 for Linux, UNIX and Windows (includes Db2 Connect Server) 11.1 and 11.5 under very specific conditions, could allow a local user to keep running a procedure that could cause the system to run out of memory.and cause a denial of service. IBM X-Force ID: 202267.

A NULL pointer dereference was found in the Linux kernel's KVM when dirty ring logging is enabled without an active vCPU context. An unprivileged local attacker on the host may use this flaw to cause a kernel oops condition and thus a denial of service by issuing a KVM_XEN_HVM_SET_ATTR ioctl. This flaw affects Linux kernel versions prior to 5.17-rc1.

An issue was discovered in the Linux kernel 2.6.39 through 5.10.16, as used in Xen. Block, net, and SCSI backends consider certain errors a plain bug, deliberately causing a kernel crash. For errors potentially being at least under the influence of guests (such as out of memory conditions), it isn't correct to assume a plain bug. Memory allocations potentially causing such crashes occur only when Linux is running in PV mode, though. This affects drivers/block/xen-blkback/blkback.c and drivers/xen/xen-scsiback.c.

An issue was discovered in the Linux kernel 3.2 through 5.10.16, as used by Xen. Grant mapping operations often occur in batch hypercalls, where a number of operations are done in a single hypercall, the success or failure of each one is reported to the backend driver, and the backend driver then loops over the results, performing follow-up actions based on the success or failure of each operation. Unfortunately, when running in PV mode, the Linux backend drivers mishandle this: Some errors are ignored, effectively implying their success from the success of related batch elements. In other cases, errors resulting from one batch element lead to further batch elements not being inspected, and hence successful ones to not be possible to properly unmap upon error recovery. Only systems with Linux backends running in PV mode are vulnerable. Linux backends run in HVM / PVH modes are not vulnerable. This affects arch/*/xen/p2m.c and drivers/xen/gntdev.c.

libata in the Linux kernel before 2.6.27.9 does not set minimum timeouts for SG_IO requests, which allows local users to cause a denial of service (Programmed I/O mode on drives) via multiple simultaneous invocations of an unspecified test program.

The key serial number collision avoidance code in the key_alloc_serial function in Linux kernel 2.6.9 up to 2.6.20 allows local users to cause a denial of service (crash) via vectors that trigger a null dereference, as originally reported as "spinlock CPU recursion."

Linux kernel 2.4.35 and other versions allows local users to send arbitrary signals to a child process that is running at higher privileges by causing a setuid-root parent process to die, which delivers an attacker-controlled parent process death signal (PR_SET_PDEATHSIG).

In Linux 2.6 before 2.6.23, the TRACE_IRQS_ON function in iret_exc calls a C function without ensuring that the segments are set properly. The kernel's %fs needs to be restored before the call in TRACE_IRQS_ON and before enabling interrupts, so that "current" references work. Without this, "current" used in the window between iret_exc and the middle of error_code where %fs is reset, would crash.

The (1) aac_cfg_open and (2) aac_compat_ioctl functions in the SCSI layer ioctl path in aacraid in the Linux kernel before 2.6.23-rc2 do not check permissions for ioctls, which might allow local users to cause a denial of service or gain privileges.

In the Linux kernel through 5.4.6, there is a NULL pointer dereference in drivers/scsi/libsas/sas_discover.c because of mishandling of port disconnection during discovery, related to a PHY down race condition, aka CID-f70267f379b5.

arch/x86/kvm/emulate.c in the KVM subsystem in the Linux kernel through 3.17.2 does not properly perform RIP changes, which allows guest OS users to cause a denial of service (guest OS crash) via a crafted application.

Arm guests can cause Dom0 DoS via PV devices When mapping pages of guests on Arm, dom0 is using an rbtree to keep track of the foreign mappings. Updating of that rbtree is not always done completely with the related lock held, resulting in a small race window, which can be used by unprivileged guests via PV devices to cause inconsistencies of the rbtree. These inconsistencies can lead to Denial of Service (DoS) of dom0, e.g. by causing crashes or the inability to perform further mappings of other guests' memory pages.

The KVM subsystem in the Linux kernel before 3.6.9, when running on hosts that use qemu userspace without XSAVE, allows local users to cause a denial of service (kernel OOPS) by using the KVM_SET_SREGS ioctl to set the X86_CR4_OSXSAVE bit in the guest cr4 register, then calling the KVM_RUN ioctl.

In the Linux kernel, the following vulnerability has been resolved: media: rkisp1: Fix IRQ disable race issue In rkisp1_isp_stop() and rkisp1_csi_disable() the driver masks the interrupts and then apparently assumes that the interrupt handler won't be running, and proceeds in the stop procedure. This is not the case, as the interrupt handler can already be running, which would lead to the ISP being disabled while the interrupt handler handling a captured frame. This brings up two issues: 1) the ISP could be powered off while the interrupt handler is still running and accessing registers, leading to board lockup, and 2) the interrupt handler code and the code that disables the streaming might do things that conflict. It is not clear to me if 2) causes a real issue, but 1) can be seen with a suitable delay (or printk in my case) in the interrupt handler, leading to board lockup.

In the Linux kernel, the following vulnerability has been resolved: net: bridge: use DEV_STATS_INC() syzbot/KCSAN reported data-races in br_handle_frame_finish() [1] This function can run from multiple cpus without mutual exclusion. Adopt SMP safe DEV_STATS_INC() to update dev->stats fields. Handles updates to dev->stats.tx_dropped while we are at it. [1] BUG: KCSAN: data-race in br_handle_frame_finish / br_handle_frame_finish read-write to 0xffff8881374b2178 of 8 bytes by interrupt on cpu 1: br_handle_frame_finish+0xd4f/0xef0 net/bridge/br_input.c:189 br_nf_hook_thresh+0x1ed/0x220 br_nf_pre_routing_finish_ipv6+0x50f/0x540 NF_HOOK include/linux/netfilter.h:304 [inline] br_nf_pre_routing_ipv6+0x1e3/0x2a0 net/bridge/br_netfilter_ipv6.c:178 br_nf_pre_routing+0x526/0xba0 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline] nf_hook_bridge_pre net/bridge/br_input.c:272 [inline] br_handle_frame+0x4c9/0x940 net/bridge/br_input.c:417 __netif_receive_skb_core+0xa8a/0x21e0 net/core/dev.c:5417 __netif_receive_skb_one_core net/core/dev.c:5521 [inline] __netif_receive_skb+0x57/0x1b0 net/core/dev.c:5637 process_backlog+0x21f/0x380 net/core/dev.c:5965 __napi_poll+0x60/0x3b0 net/core/dev.c:6527 napi_poll net/core/dev.c:6594 [inline] net_rx_action+0x32b/0x750 net/core/dev.c:6727 __do_softirq+0xc1/0x265 kernel/softirq.c:553 run_ksoftirqd+0x17/0x20 kernel/softirq.c:921 smpboot_thread_fn+0x30a/0x4a0 kernel/smpboot.c:164 kthread+0x1d7/0x210 kernel/kthread.c:388 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 read-write to 0xffff8881374b2178 of 8 bytes by interrupt on cpu 0: br_handle_frame_finish+0xd4f/0xef0 net/bridge/br_input.c:189 br_nf_hook_thresh+0x1ed/0x220 br_nf_pre_routing_finish_ipv6+0x50f/0x540 NF_HOOK include/linux/netfilter.h:304 [inline] br_nf_pre_routing_ipv6+0x1e3/0x2a0 net/bridge/br_netfilter_ipv6.c:178 br_nf_pre_routing+0x526/0xba0 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline] nf_hook_bridge_pre net/bridge/br_input.c:272 [inline] br_handle_frame+0x4c9/0x940 net/bridge/br_input.c:417 __netif_receive_skb_core+0xa8a/0x21e0 net/core/dev.c:5417 __netif_receive_skb_one_core net/core/dev.c:5521 [inline] __netif_receive_skb+0x57/0x1b0 net/core/dev.c:5637 process_backlog+0x21f/0x380 net/core/dev.c:5965 __napi_poll+0x60/0x3b0 net/core/dev.c:6527 napi_poll net/core/dev.c:6594 [inline] net_rx_action+0x32b/0x750 net/core/dev.c:6727 __do_softirq+0xc1/0x265 kernel/softirq.c:553 do_softirq+0x5e/0x90 kernel/softirq.c:454 __local_bh_enable_ip+0x64/0x70 kernel/softirq.c:381 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline] _raw_spin_unlock_bh+0x36/0x40 kernel/locking/spinlock.c:210 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_local_purge+0x1a8/0x1f0 net/batman-adv/translation-table.c:1356 batadv_tt_purge+0x2b/0x630 net/batman-adv/translation-table.c:3560 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2703 worker_thread+0x525/0x730 kernel/workqueue.c:2784 kthread+0x1d7/0x210 kernel/kthread.c:388 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 value changed: 0x00000000000d7190 -> 0x00000000000d7191 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 14848 Comm: kworker/u4:11 Not tainted 6.6.0-rc1-syzkaller-00236-gad8a69f361b9 #0

Race condition in the scan_get_next_rmap_item function in mm/ksm.c in the Linux kernel before 2.6.39.3, when Kernel SamePage Merging (KSM) is enabled, allows local users to cause a denial of service (NULL pointer dereference) or possibly have unspecified other impact via a crafted application.

In the Linux kernel, the following vulnerability has been resolved: KVM: s390: vsie: fix race during shadow creation Right now it is possible to see gmap->private being zero in kvm_s390_vsie_gmap_notifier resulting in a crash. This is due to the fact that we add gmap->private == kvm after creation: static int acquire_gmap_shadow(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) { [...] gmap = gmap_shadow(vcpu->arch.gmap, asce, edat); if (IS_ERR(gmap)) return PTR_ERR(gmap); gmap->private = vcpu->kvm; Let children inherit the private field of the parent.

Race condition in the do_add_counters function in netfilter for Linux kernel 2.6.16 allows local users with CAP_NET_ADMIN capabilities to read kernel memory by triggering the race condition in a way that produces a size value that is inconsistent with allocated memory, which leads to a buffer over-read in IPT_ENTRY_ITERATE.

In the Linux kernel, the following vulnerability has been resolved: net: nfc: fix races in nfc_llcp_sock_get() and nfc_llcp_sock_get_sn() Sili Luo reported a race in nfc_llcp_sock_get(), leading to UAF. Getting a reference on the socket found in a lookup while holding a lock should happen before releasing the lock. nfc_llcp_sock_get_sn() has a similar problem. Finally nfc_llcp_recv_snl() needs to make sure the socket found by nfc_llcp_sock_from_sn() does not disappear.

The tunnels implementation in the Linux kernel before 2.6.34, when tunnel functionality is configured as a module, allows remote attackers to cause a denial of service (OOPS) by sending a packet during module loading.

The svpn component of the F5 BIG-IP APM client prior to version 7.1.7.2 for Linux and macOS runs as a privileged process and can allow an unprivileged user to get ownership of files owned by root on the local client host in a race condition.

In the Linux kernel, the following vulnerability has been resolved: mm/sparsemem: fix race in accessing memory_section->usage The below race is observed on a PFN which falls into the device memory region with the system memory configuration where PFN's are such that [ZONE_NORMAL ZONE_DEVICE ZONE_NORMAL]. Since normal zone start and end pfn contains the device memory PFN's as well, the compaction triggered will try on the device memory PFN's too though they end up in NOP(because pfn_to_online_page() returns NULL for ZONE_DEVICE memory sections). When from other core, the section mappings are being removed for the ZONE_DEVICE region, that the PFN in question belongs to, on which compaction is currently being operated is resulting into the kernel crash with CONFIG_SPASEMEM_VMEMAP enabled. The crash logs can be seen at [1]. compact_zone() memunmap_pages ------------- --------------- __pageblock_pfn_to_page ...... (a)pfn_valid(): valid_section()//return true (b)__remove_pages()-> sparse_remove_section()-> section_deactivate(): [Free the array ms->usage and set ms->usage = NULL] pfn_section_valid() [Access ms->usage which is NULL] NOTE: From the above it can be said that the race is reduced to between the pfn_valid()/pfn_section_valid() and the section deactivate with SPASEMEM_VMEMAP enabled. The commit b943f045a9af("mm/sparse: fix kernel crash with pfn_section_valid check") tried to address the same problem by clearing the SECTION_HAS_MEM_MAP with the expectation of valid_section() returns false thus ms->usage is not accessed. Fix this issue by the below steps: a) Clear SECTION_HAS_MEM_MAP before freeing the ->usage. b) RCU protected read side critical section will either return NULL when SECTION_HAS_MEM_MAP is cleared or can successfully access ->usage. c) Free the ->usage with kfree_rcu() and set ms->usage = NULL. No attempt will be made to access ->usage after this as the SECTION_HAS_MEM_MAP is cleared thus valid_section() return false. Thanks to David/Pavan for their inputs on this patch. [1] https://lore.kernel.org/linux-mm/994410bb-89aa-d987-1f50-f514903c55aa@quicinc.com/ On Snapdragon SoC, with the mentioned memory configuration of PFN's as [ZONE_NORMAL ZONE_DEVICE ZONE_NORMAL], we are able to see bunch of issues daily while testing on a device farm. For this particular issue below is the log. Though the below log is not directly pointing to the pfn_section_valid(){ ms->usage;}, when we loaded this dump on T32 lauterbach tool, it is pointing. [ 540.578056] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 [ 540.578068] Mem abort info: [ 540.578070] ESR = 0x0000000096000005 [ 540.578073] EC = 0x25: DABT (current EL), IL = 32 bits [ 540.578077] SET = 0, FnV = 0 [ 540.578080] EA = 0, S1PTW = 0 [ 540.578082] FSC = 0x05: level 1 translation fault [ 540.578085] Data abort info: [ 540.578086] ISV = 0, ISS = 0x00000005 [ 540.578088] CM = 0, WnR = 0 [ 540.579431] pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBSBTYPE=--) [ 540.579436] pc : __pageblock_pfn_to_page+0x6c/0x14c [ 540.579454] lr : compact_zone+0x994/0x1058 [ 540.579460] sp : ffffffc03579b510 [ 540.579463] x29: ffffffc03579b510 x28: 0000000000235800 x27:000000000000000c [ 540.579470] x26: 0000000000235c00 x25: 0000000000000068 x24:ffffffc03579b640 [ 540.579477] x23: 0000000000000001 x22: ffffffc03579b660 x21:0000000000000000 [ 540.579483] x20: 0000000000235bff x19: ffffffdebf7e3940 x18:ffffffdebf66d140 [ 540.579489] x17: 00000000739ba063 x16: 00000000739ba063 x15:00000000009f4bff [ 540.579495] x14: 0000008000000000 x13: 0000000000000000 x12:0000000000000001 [ 540.579501] x11: 0000000000000000 x10: 0000000000000000 x9 :ffffff897d2cd440 [ 540.579507] x8 : 0000000000000000 x7 : 0000000000000000 x6 :ffffffc03579b5b4 [ 540.579512] x5 : 0000000000027f25 x4 : ffffffc03579b5b8 x3 :0000000000000 ---truncated---

Race in DevTools in Google Chrome prior to 145.0.7632.45 allowed a remote attacker who convinced a user to engage in specific UI gestures and install a malicious extension to potentially exploit object corruption via a malicious file. (Chromium security severity: Medium)

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix race condition between session lookup and expire Thread A + Thread B ksmbd_session_lookup | smb2_sess_setup sess = xa_load | | | xa_erase(&conn->sessions, sess->id); | | ksmbd_session_destroy(sess) --> kfree(sess) | // UAF! | sess->last_active = jiffies | + This patch add rwsem to fix race condition between ksmbd_session_lookup and ksmbd_expire_session.

In the Linux kernel, the following vulnerability has been resolved: spi: sun6i: fix race between DMA RX transfer completion and RX FIFO drain Previously the transfer complete IRQ immediately drained to RX FIFO to read any data remaining in FIFO to the RX buffer. This behaviour is correct when dealing with SPI in interrupt mode. However in DMA mode the transfer complete interrupt still fires as soon as all bytes to be transferred have been stored in the FIFO. At that point data in the FIFO still needs to be picked up by the DMA engine. Thus the drain procedure and DMA engine end up racing to read from RX FIFO, corrupting any data read. Additionally the RX buffer pointer is never adjusted according to DMA progress in DMA mode, thus calling the RX FIFO drain procedure in DMA mode is a bug. Fix corruptions in DMA RX mode by draining RX FIFO only in interrupt mode. Also wait for completion of RX DMA when in DMA mode before returning to ensure all data has been copied to the supplied memory buffer.

Race condition in the ecryptfs_mount function in fs/ecryptfs/main.c in the eCryptfs subsystem in the Linux kernel before 3.1 allows local users to bypass intended file permissions via a mount.ecryptfs_private mount with a mismatched uid.

Race condition in Google Chrome before 11.0.696.57 on Linux and Mac OS X allows remote attackers to cause a denial of service or possibly have unspecified other impact via vectors related to linked lists and a database.

Race condition in the cm_work_handler function in the InfiniBand driver (drivers/infiniband/core/cma.c) in Linux kernel 2.6.x allows remote attackers to cause a denial of service (panic) by sending an InfiniBand request while other request handlers are still running, which triggers an invalid pointer dereference.

Race condition in arch/x86/kvm/x86.c in the Linux kernel before 2.6.38 allows L2 guest OS users to cause a denial of service (L1 guest OS crash) via a crafted instruction that triggers an L2 emulation failure report, a similar issue to CVE-2014-7842.

Integer signedness error in the btrfs_ioctl_space_info function in the Linux kernel 2.6.37 allows local users to cause a denial of service (heap-based buffer overflow) or possibly have unspecified other impact via a crafted slot value.

Race condition in the sctp_icmp_proto_unreachable function in net/sctp/input.c in Linux kernel 2.6.11-rc2 through 2.6.33 allows remote attackers to cause a denial of service (panic) via an ICMP unreachable message to a socket that is already locked by a user, which causes the socket to be freed and triggers list corruption, related to the sctp_wait_for_connect function.

Race condition in the __exit_signal function in kernel/exit.c in the Linux kernel before 2.6.37-rc2 allows local users to cause a denial of service via vectors related to multithreaded exec, the use of a thread group leader in kernel/posix-cpu-timers.c, and the selection of a new thread group leader in the de_thread function in fs/exec.c.

Race condition in the mounting process in vmware-mount in VMware Workstation 7.x before 7.1.2 build 301548 on Linux, VMware Player 3.1.x before 3.1.2 build 301548 on Linux, VMware Server 2.0.2 on Linux, and VMware Fusion 3.1.x before 3.1.2 build 332101 allows host OS users to gain privileges via vectors involving temporary files.

A flaw was found in pfn_swap_entry_to_page in memory management subsystem in the Linux Kernel. In this flaw, an attacker with a local user privilege may cause a denial of service problem due to a BUG statement referencing pmd_t x.

In the Linux kernel before 4.20.8, kvm_ioctl_create_device in virt/kvm/kvm_main.c mishandles reference counting because of a race condition, leading to a use-after-free.

Race condition in kernel/events/core.c in the Linux kernel before 4.9.7 allows local users to gain privileges via a crafted application that makes concurrent perf_event_open system calls for moving a software group into a hardware context. NOTE: this vulnerability exists because of an incomplete fix for CVE-2016-6786.

In the Linux kernel, the following vulnerability has been resolved: net: ethernet: oa_tc6: fix tx skb race condition between reference pointers There are two skb pointers to manage tx skb's enqueued from n/w stack. waiting_tx_skb pointer points to the tx skb which needs to be processed and ongoing_tx_skb pointer points to the tx skb which is being processed. SPI thread prepares the tx data chunks from the tx skb pointed by the ongoing_tx_skb pointer. When the tx skb pointed by the ongoing_tx_skb is processed, the tx skb pointed by the waiting_tx_skb is assigned to ongoing_tx_skb and the waiting_tx_skb pointer is assigned with NULL. Whenever there is a new tx skb from n/w stack, it will be assigned to waiting_tx_skb pointer if it is NULL. Enqueuing and processing of a tx skb handled in two different threads. Consider a scenario where the SPI thread processed an ongoing_tx_skb and it moves next tx skb from waiting_tx_skb pointer to ongoing_tx_skb pointer without doing any NULL check. At this time, if the waiting_tx_skb pointer is NULL then ongoing_tx_skb pointer is also assigned with NULL. After that, if a new tx skb is assigned to waiting_tx_skb pointer by the n/w stack and there is a chance to overwrite the tx skb pointer with NULL in the SPI thread. Finally one of the tx skb will be left as unhandled, resulting packet missing and memory leak. - Consider the below scenario where the TXC reported from the previous transfer is 10 and ongoing_tx_skb holds an tx ethernet frame which can be transported in 20 TXCs and waiting_tx_skb is still NULL. tx_credits = 10; /* 21 are filled in the previous transfer */ ongoing_tx_skb = 20; waiting_tx_skb = NULL; /* Still NULL */ - So, (tc6->ongoing_tx_skb || tc6->waiting_tx_skb) becomes true. - After oa_tc6_prepare_spi_tx_buf_for_tx_skbs() ongoing_tx_skb = 10; waiting_tx_skb = NULL; /* Still NULL */ - Perform SPI transfer. - Process SPI rx buffer to get the TXC from footers. - Now let's assume previously filled 21 TXCs are freed so we are good to transport the next remaining 10 tx chunks from ongoing_tx_skb. tx_credits = 21; ongoing_tx_skb = 10; waiting_tx_skb = NULL; - So, (tc6->ongoing_tx_skb || tc6->waiting_tx_skb) becomes true again. - In the oa_tc6_prepare_spi_tx_buf_for_tx_skbs() ongoing_tx_skb = NULL; waiting_tx_skb = NULL; - Now the below bad case might happen, Thread1 (oa_tc6_start_xmit) Thread2 (oa_tc6_spi_thread_handler) --------------------------- ----------------------------------- - if waiting_tx_skb is NULL - if ongoing_tx_skb is NULL - ongoing_tx_skb = waiting_tx_skb - waiting_tx_skb = skb - waiting_tx_skb = NULL ... - ongoing_tx_skb = NULL - if waiting_tx_skb is NULL - waiting_tx_skb = skb To overcome the above issue, protect the moving of tx skb reference from waiting_tx_skb pointer to ongoing_tx_skb pointer and assigning new tx skb to waiting_tx_skb pointer, so that the other thread can't access the waiting_tx_skb pointer until the current thread completes moving the tx skb reference safely.