NULL Pointer Dereference

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix system hang while resume with TBT monitor [Why] Connected with a Thunderbolt monitor and do the suspend and the system may hang while resume. The TBT monitor HPD will be triggered during the resume procedure and call the drm_client_modeset_probe() while struct drm_connector connector->dev->master is NULL. It will mess up the pipe topology after resume. [How] Skip the TBT monitor HPD during the resume procedure because we currently will probe the connectors after resume by default. (cherry picked from commit 453f86a26945207a16b8f66aaed5962dc2b95b85)Show less

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix NULL deref in mlx5e_tir_builder_alloc() In mlx5e_tir_builder_alloc() kvzalloc() may return NULL which is dereferenced on the next line in a reference to the modify field. Found by Linux Verification Center (linuxtesting.org) with SVACE.Show less

In the Linux kernel, the following vulnerability has been resolved: net: dsa: improve shutdown sequence Alexander Sverdlin presents 2 problems during shutdown with the lan9303 driver. One is specific to lan9303 and the other just happens to reproduce there. The first problem is that lan9303 is unique among DSA drivers in that it calls dev_get_drvdata() at "arbitrary runtime" (not probe, not shutdown, not remove): phy_state_machine() -> ... -> dsa_user_phy_read() -> ds->ops->phy_read() -> lan9303_phy_read() -> chip->ops->phy_read() -> lan9303_mdio_phy_read() -> dev_get_drvdata() But we never stop the phy_state_machine(), so it may continue to run after dsa_switch_shutdown(). Our common pattern in all DSA drivers is to set drvdata to NULL to suppress the remove() method that may come afterwards. But in this case it will result in an NPD. The second problem is that the way in which we set dp->conduit->dsa_ptr = NULL; is concurrent with receive packet processing. dsa_switch_rcv() checks once whether dev->dsa_ptr is NULL, but afterwards, rather than continuing to use that non-NULL value, dev->dsa_ptr is dereferenced again and again without NULL checks: dsa_conduit_find_user() and many other places. In between dereferences, there is no locking to ensure that what was valid once continues to be valid. Both problems have the common aspect that closing the conduit interface solves them. In the first case, dev_close(conduit) triggers the NETDEV_GOING_DOWN event in dsa_user_netdevice_event() which closes user ports as well. dsa_port_disable_rt() calls phylink_stop(), which synchronously stops the phylink state machine, and ds->ops->phy_read() will thus no longer call into the driver after this point. In the second case, dev_close(conduit) should do this, as per Documentation/networking/driver.rst: | Quiescence | ---------- | | After the ndo_stop routine has been called, the hardware must | not receive or transmit any data. All in flight packets must | be aborted. If necessary, poll or wait for completion of | any reset commands. So it should be sufficient to ensure that later, when we zeroize conduit->dsa_ptr, there will be no concurrent dsa_switch_rcv() call on this conduit. The addition of the netif_device_detach() function is to ensure that ioctls, rtnetlinks and ethtool requests on the user ports no longer propagate down to the driver - we're no longer prepared to handle them. The race condition actually did not exist when commit 0650bf52b31f ("net: dsa: be compatible with masters which unregister on shutdown") first introduced dsa_switch_shutdown(). It was created later, when we stopped unregistering the user interfaces from a bad spot, and we just replaced that sequence with a racy zeroization of conduit->dsa_ptr (one which doesn't ensure that the interfaces aren't up).Show less

In the Linux kernel, the following vulnerability has been resolved: bpftool: Fix undefined behavior in qsort(NULL, 0, ...) When netfilter has no entry to display, qsort is called with qsort(NULL, 0, ...). This results in undefined behavior, as UBSan reports: net.c:827:2: runtime error: null pointer passed as argument 1, which is declared to never be null Although the C standard does not explicitly state whether calling qsort with a NULL pointer when the size is 0 constitutes undefined behavior, Section 7.1.4 of the C standard (Use of library functions) mentions: "Each of the following statements applies unless explicitly stated otherwise in the detailed descriptions that follow: If an argument to a function has an invalid value (such as a value outside the domain of the function, or a pointer outside the address space of the program, or a null pointer, or a pointer to non-modifiable storage when the corresponding parameter is not const-qualified) or a type (after promotion) not expected by a function with variable number of arguments, the behavior is undefined." To avoid this, add an early return when nf_link_info is NULL to prevent calling qsort with a NULL pointer.Show less

In the Linux kernel, the following vulnerability has been resolved: net: gso: fix tcp fraglist segmentation after pull from frag_list Detect tcp gso fraglist skbs with corrupted geometry (see below) and pass these to skb_segment instead of skb_segment_list, as the first can segment them correctly. Valid SKB_GSO_FRAGLIST skbs - consist of two or more segments - the head_skb holds the protocol headers plus first gso_size - one or more frag_list skbs hold exactly one segment - all but the last must be gso_size Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can modify these skbs, breaking these invariants. In extreme cases they pull all data into skb linear. For TCP, this causes a NULL ptr deref in __tcpv4_gso_segment_list_csum at tcp_hdr(seg->next). Detect invalid geometry due to pull, by checking head_skb size. Don't just drop, as this may blackhole a destination. Convert to be able to pass to regular skb_segment. Approach and description based on a patch by Willem de Bruijn.Show less

In the Linux kernel, the following vulnerability has been resolved: gso: fix udp gso fraglist segmentation after pull from frag_list Detect gso fraglist skbs with corrupted geometry (see below) and pass these to skb_segment instead of skb_segment_list, as the first can segment them correctly. Valid SKB_GSO_FRAGLIST skbs - consist of two or more segments - the head_skb holds the protocol headers plus first gso_size - one or more frag_list skbs hold exactly one segment - all but the last must be gso_size Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can modify these skbs, breaking these invariants. In extreme cases they pull all data into skb linear. For UDP, this causes a NULL ptr deref in __udpv4_gso_segment_list_csum at udp_hdr(seg->next)->dest. Detect invalid geometry due to pull, by checking head_skb size. Don't just drop, as this may blackhole a destination. Convert to be able to pass to regular skb_segment.Show less

In the Linux kernel, the following vulnerability has been resolved: ACPICA: check null return of ACPI_ALLOCATE_ZEROED() in acpi_db_convert_to_package() ACPICA commit 4d4547cf13cca820ff7e0f859ba83e1a610b9fd0 ACPI_ALLOCATE_ZEROED() may fail, elements might be NULL and will cause NULL pointer dereference later. [ rjw: Subject and changelog edits ]Show less

In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix null-ptr-deref when journal load failed. During the mounting process, if journal_reset() fails because of too short journal, then lead to jbd2_journal_load() fails with NULL j_sb_buffer. Subsequently, ocfs2_journal_shutdown() calls jbd2_journal_flush()->jbd2_cleanup_journal_tail()-> __jbd2_update_log_tail()->jbd2_journal_update_sb_log_tail() ->lock_buffer(journal->j_sb_buffer), resulting in a null-pointer dereference error. To resolve this issue, we should check the JBD2_LOADED flag to ensure the journal was properly loaded. Additionally, use journal instead of osb->journal directly to simplify the code.Show less

In the Linux kernel, the following vulnerability has been resolved: gfs2: fix double destroy_workqueue error When gfs2_fill_super() fails, destroy_workqueue() is called within gfs2_gl_hash_clear(), and the subsequent code path calls destroy_workqueue() on the same work queue again. This issue can be fixed by setting the work queue pointer to NULL after the first destroy_workqueue() call and checking for a NULL pointer before attempting to destroy the work queue again.Show less

In the Linux kernel, the following vulnerability has been resolved: net: avoid potential underflow in qdisc_pkt_len_init() with UFO After commit 7c6d2ecbda83 ("net: be more gentle about silly gso requests coming from user") virtio_net_hdr_to_skb() had sanity check to detect malicious attempts from user space to cook a bad GSO packet. Then commit cf9acc90c80ec ("net: virtio_net_hdr_to_skb: count transport header in UFO") while fixing one issue, allowed user space to cook a GSO packet with the following characteristic : IPv4 SKB_GSO_UDP, gso_size=3, skb->len = 28. When this packet arrives in qdisc_pkt_len_init(), we end up with hdr_len = 28 (IPv4 header + UDP header), matching skb->len Then the following sets gso_segs to 0 : gso_segs = DIV_ROUND_UP(skb->len - hdr_len, shinfo->gso_size); Then later we set qdisc_skb_cb(skb)->pkt_len to back to zero :/ qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len; This leads to the following crash in fq_codel [1] qdisc_pkt_len_init() is best effort, we only want an estimation of the bytes sent on the wire, not crashing the kernel. This patch is fixing this particular issue, a following one adds more sanity checks for another potential bug. [1] [ 70.724101] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 70.724561] #PF: supervisor read access in kernel mode [ 70.724561] #PF: error_code(0x0000) - not-present page [ 70.724561] PGD 10ac61067 P4D 10ac61067 PUD 107ee2067 PMD 0 [ 70.724561] Oops: Oops: 0000 [#1] SMP NOPTI [ 70.724561] CPU: 11 UID: 0 PID: 2163 Comm: b358537762 Not tainted 6.11.0-virtme #991 [ 70.724561] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 70.724561] RIP: 0010:fq_codel_enqueue (net/sched/sch_fq_codel.c:120 net/sched/sch_fq_codel.c:168 net/sched/sch_fq_codel.c:230) sch_fq_codel [ 70.724561] Code: 24 08 49 c1 e1 06 44 89 7c 24 18 45 31 ed 45 31 c0 31 ff 89 44 24 14 4c 03 8b 90 01 00 00 eb 04 39 ca 73 37 4d 8b 39 83 c7 01 <49> 8b 17 49 89 11 41 8b 57 28 45 8b 5f 34 49 c7 07 00 00 00 00 49 All code ======== 0: 24 08 and $0x8,%al 2: 49 c1 e1 06 shl $0x6,%r9 6: 44 89 7c 24 18 mov %r15d,0x18(%rsp) b: 45 31 ed xor %r13d,%r13d e: 45 31 c0 xor %r8d,%r8d 11: 31 ff xor %edi,%edi 13: 89 44 24 14 mov %eax,0x14(%rsp) 17: 4c 03 8b 90 01 00 00 add 0x190(%rbx),%r9 1e: eb 04 jmp 0x24 20: 39 ca cmp %ecx,%edx 22: 73 37 jae 0x5b 24: 4d 8b 39 mov (%r9),%r15 27: 83 c7 01 add $0x1,%edi 2a:* 49 8b 17 mov (%r15),%rdx <-- trapping instruction 2d: 49 89 11 mov %rdx,(%r9) 30: 41 8b 57 28 mov 0x28(%r15),%edx 34: 45 8b 5f 34 mov 0x34(%r15),%r11d 38: 49 c7 07 00 00 00 00 movq $0x0,(%r15) 3f: 49 rex.WB Code starting with the faulting instruction =========================================== 0: 49 8b 17 mov (%r15),%rdx 3: 49 89 11 mov %rdx,(%r9) 6: 41 8b 57 28 mov 0x28(%r15),%edx a: 45 8b 5f 34 mov 0x34(%r15),%r11d e: 49 c7 07 00 00 00 00 movq $0x0,(%r15) 15: 49 rex.WB [ 70.724561] RSP: 0018:ffff95ae85e6fb90 EFLAGS: 00000202 [ 70.724561] RAX: 0000000002000000 RBX: ffff95ae841de000 RCX: 0000000000000000 [ 70.724561] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 [ 70.724561] RBP: ffff95ae85e6fbf8 R08: 0000000000000000 R09: ffff95b710a30000 [ 70.724561] R10: 0000000000000000 R11: bdf289445ce31881 R12: ffff95ae85e6fc58 [ 70.724561] R13: 0000000000000000 R14: 0000000000000040 R15: 0000000000000000 [ 70.724561] FS: 000000002c5c1380(0000) GS:ffff95bd7fcc0000(0000) knlGS:0000000000000000 [ 70.724561] CS: 0010 DS: 0000 ES: 0000 C ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: drm/xe: Prevent null pointer access in xe_migrate_copy xe_migrate_copy designed to copy content of TTM resources. When source resource is null, it will trigger a NULL pointer dereference in xe_migrate_copy. To avoid this situation, update lacks source flag to true for this case, the flag will trigger xe_migrate_clear rather than xe_migrate_copy. Issue trace: <7> [317.089847] xe 0000:00:02.0: [drm:xe_migrate_copy [xe]] Pass 14, sizes: 4194304 & 4194304 <7> [317.089945] xe 0000:00:02.0: [drm:xe_migrate_copy [xe]] Pass 15, sizes: 4194304 & 4194304 <1> [317.128055] BUG: kernel NULL pointer dereference, address: 0000000000000010 <1> [317.128064] #PF: supervisor read access in kernel mode <1> [317.128066] #PF: error_code(0x0000) - not-present page <6> [317.128069] PGD 0 P4D 0 <4> [317.128071] Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI <4> [317.128074] CPU: 1 UID: 0 PID: 1440 Comm: kunit_try_catch Tainted: G U N 6.11.0-rc7-xe #1 <4> [317.128078] Tainted: [U]=USER, [N]=TEST <4> [317.128080] Hardware name: Intel Corporation Lunar Lake Client Platform/LNL-M LP5 RVP1, BIOS LNLMFWI1.R00.3221.D80.2407291239 07/29/2024 <4> [317.128082] RIP: 0010:xe_migrate_copy+0x66/0x13e0 [xe] <4> [317.128158] Code: 00 00 48 89 8d e0 fe ff ff 48 8b 40 10 4c 89 85 c8 fe ff ff 44 88 8d bd fe ff ff 65 48 8b 3c 25 28 00 00 00 48 89 7d d0 31 ff <8b> 79 10 48 89 85 a0 fe ff ff 48 8b 00 48 89 b5 d8 fe ff ff 83 ff <4> [317.128162] RSP: 0018:ffffc9000167f9f0 EFLAGS: 00010246 <4> [317.128164] RAX: ffff8881120d8028 RBX: ffff88814d070428 RCX: 0000000000000000 <4> [317.128166] RDX: ffff88813cb99c00 RSI: 0000000004000000 RDI: 0000000000000000 <4> [317.128168] RBP: ffffc9000167fbb8 R08: ffff88814e7b1f08 R09: 0000000000000001 <4> [317.128170] R10: 0000000000000001 R11: 0000000000000001 R12: ffff88814e7b1f08 <4> [317.128172] R13: ffff88814e7b1f08 R14: ffff88813cb99c00 R15: 0000000000000001 <4> [317.128174] FS: 0000000000000000(0000) GS:ffff88846f280000(0000) knlGS:0000000000000000 <4> [317.128176] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 <4> [317.128178] CR2: 0000000000000010 CR3: 000000011f676004 CR4: 0000000000770ef0 <4> [317.128180] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 <4> [317.128182] DR3: 0000000000000000 DR6: 00000000ffff07f0 DR7: 0000000000000400 <4> [317.128184] PKRU: 55555554 <4> [317.128185] Call Trace: <4> [317.128187] <TASK> <4> [317.128189] ? show_regs+0x67/0x70 <4> [317.128194] ? __die_body+0x20/0x70 <4> [317.128196] ? __die+0x2b/0x40 <4> [317.128198] ? page_fault_oops+0x15f/0x4e0 <4> [317.128203] ? do_user_addr_fault+0x3fb/0x970 <4> [317.128205] ? lock_acquire+0xc7/0x2e0 <4> [317.128209] ? exc_page_fault+0x87/0x2b0 <4> [317.128212] ? asm_exc_page_fault+0x27/0x30 <4> [317.128216] ? xe_migrate_copy+0x66/0x13e0 [xe] <4> [317.128263] ? __lock_acquire+0xb9d/0x26f0 <4> [317.128265] ? __lock_acquire+0xb9d/0x26f0 <4> [317.128267] ? sg_free_append_table+0x20/0x80 <4> [317.128271] ? lock_acquire+0xc7/0x2e0 <4> [317.128273] ? mark_held_locks+0x4d/0x80 <4> [317.128275] ? trace_hardirqs_on+0x1e/0xd0 <4> [317.128278] ? _raw_spin_unlock_irqrestore+0x31/0x60 <4> [317.128281] ? __pm_runtime_resume+0x60/0xa0 <4> [317.128284] xe_bo_move+0x682/0xc50 [xe] <4> [317.128315] ? lock_is_held_type+0xaa/0x120 <4> [317.128318] ttm_bo_handle_move_mem+0xe5/0x1a0 [ttm] <4> [317.128324] ttm_bo_validate+0xd1/0x1a0 [ttm] <4> [317.128328] shrink_test_run_device+0x721/0xc10 [xe] <4> [317.128360] ? find_held_lock+0x31/0x90 <4> [317.128363] ? lock_release+0xd1/0x2a0 <4> [317.128365] ? __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10 [kunit] <4> [317.128370] xe_bo_shrink_kunit+0x11/0x20 [xe] <4> [317.128397] kunit_try_run_case+0x6e/0x150 [kunit] <4> [317.128400] ? trace_hardirqs_on+0x1e/0xd0 <4> [317.128402] ? _raw_spin_unlock_irqrestore+0x31/0x60 <4> [317.128404] kunit_generic_run_threadfn_adapter+0x1e/0x40 [ku ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: gpiolib: Fix potential NULL pointer dereference in gpiod_get_label() In `gpiod_get_label()`, it is possible that `srcu_dereference_check()` may return a NULL pointer, leading to a scenario where `label->str` is accessed without verifying if `label` itself is NULL. This patch adds a proper NULL check for `label` before accessing `label->str`. The check for `label->str != NULL` is removed because `label->str` can never be NULL if `label` is not NULL. This fixes the issue where the label name was being printed as `(efault)` when dumping the sysfs GPIO file when `label == NULL`.Show less

In the Linux kernel, the following vulnerability has been resolved: wifi: iwlwifi: mvm: avoid NULL pointer dereference iwl_mvm_tx_skb_sta() and iwl_mvm_tx_mpdu() verify that the mvmvsta pointer is not NULL. It retrieves this pointer using iwl_mvm_sta_from_mac80211, which is dereferencing the ieee80211_sta pointer. If sta is NULL, iwl_mvm_sta_from_mac80211 will dereference a NULL pointer. Fix this by checking the sta pointer before retrieving the mvmsta from it. If sta is not NULL, then mvmsta isn't either.Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Pass non-null to dcn20_validate_apply_pipe_split_flags [WHAT & HOW] "dcn20_validate_apply_pipe_split_flags" dereferences merge, and thus it cannot be a null pointer. Let's pass a valid pointer to avoid null dereference. This fixes 2 FORWARD_NULL issues reported by Coverity.Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Check null pointers before using them [WHAT & HOW] These pointers are null checked previously in the same function, indicating they might be null as reported by Coverity. As a result, they need to be checked when used again. This fixes 3 FORWARD_NULL issue reported by Coverity.Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Check null pointers before used [WHAT & HOW] Poniters, such as dc->clk_mgr, are null checked previously in the same function, so Coverity warns "implies that "dc->clk_mgr" might be null". As a result, these pointers need to be checked when used again. This fixes 10 FORWARD_NULL issues reported by Coverity.Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Check null pointers before multiple uses [WHAT & HOW] Poniters, such as stream_enc and dc->bw_vbios, are null checked previously in the same function, so Coverity warns "implies that stream_enc and dc->bw_vbios might be null". They are used multiple times in the subsequent code and need to be checked. This fixes 10 FORWARD_NULL issues reported by Coverity.Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add null check for head_pipe in dcn201_acquire_free_pipe_for_layer This commit addresses a potential null pointer dereference issue in the `dcn201_acquire_free_pipe_for_layer` function. The issue could occur when `head_pipe` is null. The fix adds a check to ensure `head_pipe` is not null before asserting it. If `head_pipe` is null, the function returns NULL to prevent a potential null pointer dereference. Reported by smatch: drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn201/dcn201_resource.c:1016 dcn201_acquire_free_pipe_for_layer() error: we previously assumed 'head_pipe' could be null (see line 1010)Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add null check for head_pipe in dcn32_acquire_idle_pipe_for_head_pipe_in_layer This commit addresses a potential null pointer dereference issue in the `dcn32_acquire_idle_pipe_for_head_pipe_in_layer` function. The issue could occur when `head_pipe` is null. The fix adds a check to ensure `head_pipe` is not null before asserting it. If `head_pipe` is null, the function returns NULL to prevent a potential null pointer dereference. Reported by smatch: drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn32/dcn32_resource.c:2690 dcn32_acquire_idle_pipe_for_head_pipe_in_layer() error: we previously assumed 'head_pipe' could be null (see line 2681)Show less

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Add NULL check for clk_mgr and clk_mgr->funcs in dcn30_init_hw This commit addresses a potential null pointer dereference issue in the `dcn30_init_hw` function. The issue could occur when `dc->clk_mgr` or `dc->clk_mgr->funcs` is null. The fix adds a check to ensure `dc->clk_mgr` and `dc->clk_mgr->funcs` is not null before accessing its functions. This prevents a potential null pointer dereference. Reported by smatch: drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn30/dcn30_hwseq.c:789 dcn30_init_hw() error: we previously assumed 'dc->clk_mgr' could be null (see line 628)Show less