NULL Pointer Dereference

In the Linux kernel, the following vulnerability has been resolved: s390/bpf: Fix bpf_plt pointer arithmetic Kui-Feng Lee reported a crash on s390x triggered by the dummy_st_ops/dummy_init_ptr_arg test [1]: [<0000000000000002>] 0x2 [<00000000009d5cde>] bpf_struct_ops_test_run+0x156/0x250 [<000000000033145a>] __sys_bpf+0xa1a/0xd00 [<00000000003319dc>] __s390x_sys_bpf+0x44/0x50 [<0000000000c4382c>] __do_syscall+0x244/0x300 [<0000000000c59a40>] system_call+0x70/0x98 This is caused by GCC moving memcpy() after assignments in bpf_jit_plt(), resulting in NULL pointers being written instead of the return and the target addresses. Looking at the GCC internals, the reordering is allowed because the alias analysis thinks that the memcpy() destination and the assignments' left-hand-sides are based on different objects: new_plt and bpf_plt_ret/bpf_plt_target respectively, and therefore they cannot alias. This is in turn due to a violation of the C standard: When two pointers are subtracted, both shall point to elements of the same array object, or one past the last element of the array object ... From the C's perspective, bpf_plt_ret and bpf_plt are distinct objects and cannot be subtracted. In the practical terms, doing so confuses the GCC's alias analysis. The code was written this way in order to let the C side know a few offsets defined in the assembly. While nice, this is by no means necessary. Fix the noncompliance by hardcoding these offsets. [1] https://lore.kernel.org/bpf/c9923c1d-971d-4022-8dc8-1364e929d34c@gmail.com/Show less

In the Linux kernel, the following vulnerability has been resolved: dma-buf: Fix NULL pointer dereference in sanitycheck() If due to a memory allocation failure mock_chain() returns NULL, it is passed to dma_fence_enable_sw_signaling() resulting in NULL pointer dereference there. Call dma_fence_enable_sw_signaling() only if mock_chain() succeeds. Found by Linux Verification Center (linuxtesting.org) with SVACE.Show less

In the Linux kernel, the following vulnerability has been resolved: mlxbf_gige: call request_irq() after NAPI initialized The mlxbf_gige driver encounters a NULL pointer exception in mlxbf_gige_open() when kdump is enabled. The sequence to reproduce the exception is as follows: a) enable kdump b) trigger kdump via "echo c > /proc/sysrq-trigger" c) kdump kernel executes d) kdump kernel loads mlxbf_gige module e) the mlxbf_gige module runs its open() as the the "oob_net0" interface is brought up f) mlxbf_gige module will experience an exception during its open(), something like: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 Mem abort info: ESR = 0x0000000086000004 EC = 0x21: IABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x04: level 0 translation fault user pgtable: 4k pages, 48-bit VAs, pgdp=00000000e29a4000 [0000000000000000] pgd=0000000000000000, p4d=0000000000000000 Internal error: Oops: 0000000086000004 [#1] SMP CPU: 0 PID: 812 Comm: NetworkManager Tainted: G OE 5.15.0-1035-bluefield #37-Ubuntu Hardware name: https://www.mellanox.com BlueField-3 SmartNIC Main Card/BlueField-3 SmartNIC Main Card, BIOS 4.6.0.13024 Jan 19 2024 pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : 0x0 lr : __napi_poll+0x40/0x230 sp : ffff800008003e00 x29: ffff800008003e00 x28: 0000000000000000 x27: 00000000ffffffff x26: ffff000066027238 x25: ffff00007cedec00 x24: ffff800008003ec8 x23: 000000000000012c x22: ffff800008003eb7 x21: 0000000000000000 x20: 0000000000000001 x19: ffff000066027238 x18: 0000000000000000 x17: ffff578fcb450000 x16: ffffa870b083c7c0 x15: 0000aaab010441d0 x14: 0000000000000001 x13: 00726f7272655f65 x12: 6769675f6662786c x11: 0000000000000000 x10: 0000000000000000 x9 : ffffa870b0842398 x8 : 0000000000000004 x7 : fe5a48b9069706ea x6 : 17fdb11fc84ae0d2 x5 : d94a82549d594f35 x4 : 0000000000000000 x3 : 0000000000400100 x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff000066027238 Call trace: 0x0 net_rx_action+0x178/0x360 __do_softirq+0x15c/0x428 __irq_exit_rcu+0xac/0xec irq_exit+0x18/0x2c handle_domain_irq+0x6c/0xa0 gic_handle_irq+0xec/0x1b0 call_on_irq_stack+0x20/0x2c do_interrupt_handler+0x5c/0x70 el1_interrupt+0x30/0x50 el1h_64_irq_handler+0x18/0x2c el1h_64_irq+0x7c/0x80 __setup_irq+0x4c0/0x950 request_threaded_irq+0xf4/0x1bc mlxbf_gige_request_irqs+0x68/0x110 [mlxbf_gige] mlxbf_gige_open+0x5c/0x170 [mlxbf_gige] __dev_open+0x100/0x220 __dev_change_flags+0x16c/0x1f0 dev_change_flags+0x2c/0x70 do_setlink+0x220/0xa40 __rtnl_newlink+0x56c/0x8a0 rtnl_newlink+0x58/0x84 rtnetlink_rcv_msg+0x138/0x3c4 netlink_rcv_skb+0x64/0x130 rtnetlink_rcv+0x20/0x30 netlink_unicast+0x2ec/0x360 netlink_sendmsg+0x278/0x490 __sock_sendmsg+0x5c/0x6c ____sys_sendmsg+0x290/0x2d4 ___sys_sendmsg+0x84/0xd0 __sys_sendmsg+0x70/0xd0 __arm64_sys_sendmsg+0x2c/0x40 invoke_syscall+0x78/0x100 el0_svc_common.constprop.0+0x54/0x184 do_el0_svc+0x30/0xac el0_svc+0x48/0x160 el0t_64_sync_handler+0xa4/0x12c el0t_64_sync+0x1a4/0x1a8 Code: bad PC value ---[ end trace 7d1c3f3bf9d81885 ]--- Kernel panic - not syncing: Oops: Fatal exception in interrupt Kernel Offset: 0x2870a7a00000 from 0xffff800008000000 PHYS_OFFSET: 0x80000000 CPU features: 0x0,000005c1,a3332a5a Memory Limit: none ---[ end Kernel panic - not syncing: Oops: Fatal exception in interrupt ]--- The exception happens because there is a pending RX interrupt before the call to request_irq(RX IRQ) executes. Then, the RX IRQ handler fires immediately after this request_irq() completes. The ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: selinux: avoid dereference of garbage after mount failure In case kern_mount() fails and returns an error pointer return in the error branch instead of continuing and dereferencing the error pointer. While on it drop the never read static variable selinuxfs_mount.Show less

In the Linux kernel, the following vulnerability has been resolved: net/rds: fix possible cp null dereference cp might be null, calling cp->cp_conn would produce null dereference [Simon Horman adds:] Analysis: * cp is a parameter of __rds_rdma_map and is not reassigned. * The following call-sites pass a NULL cp argument to __rds_rdma_map() - rds_get_mr() - rds_get_mr_for_dest * Prior to the code above, the following assumes that cp may be NULL (which is indicative, but could itself be unnecessary) trans_private = rs->rs_transport->get_mr( sg, nents, rs, &mr->r_key, cp ? cp->cp_conn : NULL, args->vec.addr, args->vec.bytes, need_odp ? ODP_ZEROBASED : ODP_NOT_NEEDED); * The code modified by this patch is guarded by IS_ERR(trans_private), where trans_private is assigned as per the previous point in this analysis. The only implementation of get_mr that I could locate is rds_ib_get_mr() which can return an ERR_PTR if the conn (4th) argument is NULL. * ret is set to PTR_ERR(trans_private). rds_ib_get_mr can return ERR_PTR(-ENODEV) if the conn (4th) argument is NULL. Thus ret may be -ENODEV in which case the code in question will execute. Conclusion: * cp may be NULL at the point where this patch adds a check; this patch does seem to address a possible bugShow less

In the Linux kernel, the following vulnerability has been resolved: net: phy: micrel: Fix potential null pointer dereference In lan8814_get_sig_rx() and lan8814_get_sig_tx() ptp_parse_header() may return NULL as ptp_header due to abnormal packet type or corrupted packet. Fix this bug by adding ptp_header check. Found by Linux Verification Center (linuxtesting.org) with SVACE.Show less

In the Linux kernel, the following vulnerability has been resolved: mlxbf_gige: stop interface during shutdown The mlxbf_gige driver intermittantly encounters a NULL pointer exception while the system is shutting down via "reboot" command. The mlxbf_driver will experience an exception right after executing its shutdown() method. One example of this exception is: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000070 Mem abort info: ESR = 0x0000000096000004 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x04: level 0 translation fault Data abort info: ISV = 0, ISS = 0x00000004 CM = 0, WnR = 0 user pgtable: 4k pages, 48-bit VAs, pgdp=000000011d373000 [0000000000000070] pgd=0000000000000000, p4d=0000000000000000 Internal error: Oops: 96000004 [#1] SMP CPU: 0 PID: 13 Comm: ksoftirqd/0 Tainted: G S OE 5.15.0-bf.6.gef6992a #1 Hardware name: https://www.mellanox.com BlueField SoC/BlueField SoC, BIOS 4.0.2.12669 Apr 21 2023 pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : mlxbf_gige_handle_tx_complete+0xc8/0x170 [mlxbf_gige] lr : mlxbf_gige_poll+0x54/0x160 [mlxbf_gige] sp : ffff8000080d3c10 x29: ffff8000080d3c10 x28: ffffcce72cbb7000 x27: ffff8000080d3d58 x26: ffff0000814e7340 x25: ffff331cd1a05000 x24: ffffcce72c4ea008 x23: ffff0000814e4b40 x22: ffff0000814e4d10 x21: ffff0000814e4128 x20: 0000000000000000 x19: ffff0000814e4a80 x18: ffffffffffffffff x17: 000000000000001c x16: ffffcce72b4553f4 x15: ffff80008805b8a7 x14: 0000000000000000 x13: 0000000000000030 x12: 0101010101010101 x11: 7f7f7f7f7f7f7f7f x10: c2ac898b17576267 x9 : ffffcce720fa5404 x8 : ffff000080812138 x7 : 0000000000002e9a x6 : 0000000000000080 x5 : ffff00008de3b000 x4 : 0000000000000000 x3 : 0000000000000001 x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: mlxbf_gige_handle_tx_complete+0xc8/0x170 [mlxbf_gige] mlxbf_gige_poll+0x54/0x160 [mlxbf_gige] __napi_poll+0x40/0x1c8 net_rx_action+0x314/0x3a0 __do_softirq+0x128/0x334 run_ksoftirqd+0x54/0x6c smpboot_thread_fn+0x14c/0x190 kthread+0x10c/0x110 ret_from_fork+0x10/0x20 Code: 8b070000 f9000ea0 f95056c0 f86178a1 (b9407002) ---[ end trace 7cc3941aa0d8e6a4 ]--- Kernel panic - not syncing: Oops: Fatal exception in interrupt Kernel Offset: 0x4ce722520000 from 0xffff800008000000 PHYS_OFFSET: 0x80000000 CPU features: 0x000005c1,a3330e5a Memory Limit: none ---[ end Kernel panic - not syncing: Oops: Fatal exception in interrupt ]--- During system shutdown, the mlxbf_gige driver's shutdown() is always executed. However, the driver's stop() method will only execute if networking interface configuration logic within the Linux distribution has been setup to do so. If shutdown() executes but stop() does not execute, NAPI remains enabled and this can lead to an exception if NAPI is scheduled while the hardware interface has only been partially deinitialized. The networking interface managed by the mlxbf_gige driver must be properly stopped during system shutdown so that IFF_UP is cleared, the hardware interface is put into a clean state, and NAPI is fully deinitialized.Show less

In the Linux kernel, the following vulnerability has been resolved: spi: mchp-pci1xxx: Fix a possible null pointer dereference in pci1xxx_spi_probe In function pci1xxxx_spi_probe, there is a potential null pointer that may be caused by a failed memory allocation by the function devm_kzalloc. Hence, a null pointer check needs to be added to prevent null pointer dereferencing later in the code. To fix this issue, spi_bus->spi_int[iter] should be checked. The memory allocated by devm_kzalloc will be automatically released, so just directly return -ENOMEM without worrying about memory leaks.Show less

In the Linux kernel, the following vulnerability has been resolved: of: module: prevent NULL pointer dereference in vsnprintf() In of_modalias(), we can get passed the str and len parameters which would cause a kernel oops in vsnprintf() since it only allows passing a NULL ptr when the length is also 0. Also, we need to filter out the negative values of the len parameter as these will result in a really huge buffer since snprintf() takes size_t parameter while ours is ssize_t... Found by Linux Verification Center (linuxtesting.org) with the Svace static analysis tool.Show less

In the Linux kernel, the following vulnerability has been resolved: aio: Fix null ptr deref in aio_complete() wakeup list_del_init_careful() needs to be the last access to the wait queue entry - it effectively unlocks access. Previously, finish_wait() would see the empty list head and skip taking the lock, and then we'd return - but the completion path would still attempt to do the wakeup after the task_struct pointer had been overwritten.Show less

In the Linux kernel, the following vulnerability has been resolved: icmp: prevent possible NULL dereferences from icmp_build_probe() First problem is a double call to __in_dev_get_rcu(), because the second one could return NULL. if (__in_dev_get_rcu(dev) && __in_dev_get_rcu(dev)->ifa_list) Second problem is a read from dev->ip6_ptr with no NULL check: if (!list_empty(&rcu_dereference(dev->ip6_ptr)->addr_list)) Use the correct RCU API to fix these. v2: add missing include <net/addrconf.h>Show less

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: qca: fix NULL-deref on non-serdev suspend Qualcomm ROME controllers can be registered from the Bluetooth line discipline and in this case the HCI UART serdev pointer is NULL. Add the missing sanity check to prevent a NULL-pointer dereference when wakeup() is called for a non-serdev controller during suspend. Just return true for now to restore the original behaviour and address the crash with pre-6.2 kernels, which do not have commit e9b3e5b8c657 ("Bluetooth: hci_qca: only assign wakeup with serial port support") that causes the crash to happen already at setup() time.Show less

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: qca: fix NULL-deref on non-serdev setup Qualcomm ROME controllers can be registered from the Bluetooth line discipline and in this case the HCI UART serdev pointer is NULL. Add the missing sanity check to prevent a NULL-pointer dereference when setup() is called for a non-serdev controller.Show less

In the Linux kernel, the following vulnerability has been resolved: mm: zswap: fix shrinker NULL crash with cgroup_disable=memory Christian reports a NULL deref in zswap that he bisected down to the zswap shrinker. The issue also cropped up in the bug trackers of libguestfs [1] and the Red Hat bugzilla [2]. The problem is that when memcg is disabled with the boot time flag, the zswap shrinker might get called with sc->memcg == NULL. This is okay in many places, like the lruvec operations. But it crashes in memcg_page_state() - which is only used due to the non-node accounting of cgroup's the zswap memory to begin with. Nhat spotted that the memcg can be NULL in the memcg-disabled case, and I was then able to reproduce the crash locally as well. [1] https://github.com/libguestfs/libguestfs/issues/139 [2] https://bugzilla.redhat.com/show_bug.cgi?id=2275252Show less

In the Linux kernel, the following vulnerability has been resolved: ASoC: mediatek: sof-common: Add NULL check for normal_link string It's not granted that all entries of struct sof_conn_stream declare a `normal_link` (a non-SOF, direct link) string, and this is the case for SoCs that support only SOF paths (hence do not support both direct and SOF usecases). For example, in the case of MT8188 there is no normal_link string in any of the sof_conn_stream entries and there will be more drivers doing that in the future. To avoid possible NULL pointer KPs, add a NULL check for `normal_link`.Show less

In the Linux kernel, the following vulnerability has been resolved: powerpc/powernv: Add a null pointer check in opal_powercap_init() kasprintf() returns a pointer to dynamically allocated memory which can be NULL upon failure.Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Check writeback connectors in create_validate_stream_for_sink [WHY & HOW] This is to check connector type to avoid unhandled null pointer for writeback connectors.Show less

In the Linux kernel, the following vulnerability has been resolved: powerpc/powernv: Add a null pointer check to scom_debug_init_one() kasprintf() returns a pointer to dynamically allocated memory which can be NULL upon failure. Add a null pointer check, and release 'ent' to avoid memory leaks.Show less

In the Linux kernel, the following vulnerability has been resolved: powerpc/powernv: Add a null pointer check in opal_event_init() kasprintf() returns a pointer to dynamically allocated memory which can be NULL upon failure.Show less

In the Linux kernel, the following vulnerability has been resolved: powerpc/imc-pmu: Add a null pointer check in update_events_in_group() kasprintf() returns a pointer to dynamically allocated memory which can be NULL upon failure.Show less