Linux

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix missing free nid in f2fs_handle_failed_inode This patch fixes xfstests/generic/475 failure. [ 293.680694] F2FS-fs (dm-1): May loss orphan inode, run fsck to fix. [ 293.685358] Buffer I/O error on dev dm-1, logical block 8388592, async page read [ 293.691527] Buffer I/O error on dev dm-1, logical block 8388592, async page read [ 293.691764] sh (7615): drop_caches: 3 [ 293.691819] sh (7616): drop_caches: 3 [ 293.694017] Buffer I/O error on dev dm-1, logical block 1, async page read [ 293.695659] sh (7618): drop_caches: 3 [ 293.696979] sh (7617): drop_caches: 3 [ 293.700290] sh (7623): drop_caches: 3 [ 293.708621] sh (7626): drop_caches: 3 [ 293.711386] sh (7628): drop_caches: 3 [ 293.711825] sh (7627): drop_caches: 3 [ 293.716738] sh (7630): drop_caches: 3 [ 293.719613] sh (7632): drop_caches: 3 [ 293.720971] sh (7633): drop_caches: 3 [ 293.727741] sh (7634): drop_caches: 3 [ 293.730783] sh (7636): drop_caches: 3 [ 293.732681] sh (7635): drop_caches: 3 [ 293.732988] sh (7637): drop_caches: 3 [ 293.738836] sh (7639): drop_caches: 3 [ 293.740568] sh (7641): drop_caches: 3 [ 293.743053] sh (7640): drop_caches: 3 [ 293.821889] ------------[ cut here ]------------ [ 293.824654] kernel BUG at fs/f2fs/node.c:3334! [ 293.826226] invalid opcode: 0000 [#1] PREEMPT SMP PTI [ 293.828713] CPU: 0 PID: 7653 Comm: umount Tainted: G OE 5.17.0-rc1-custom #1 [ 293.830946] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 [ 293.832526] RIP: 0010:f2fs_destroy_node_manager+0x33f/0x350 [f2fs] [ 293.833905] Code: e8 d6 3d f9 f9 48 8b 45 d0 65 48 2b 04 25 28 00 00 00 75 1a 48 81 c4 28 03 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 0b [ 293.837783] RSP: 0018:ffffb04ec31e7a20 EFLAGS: 00010202 [ 293.839062] RAX: 0000000000000001 RBX: ffff9df947db2eb8 RCX: 0000000080aa0072 [ 293.840666] RDX: 0000000000000000 RSI: ffffe86c0432a140 RDI: ffffffffc0b72a21 [ 293.842261] RBP: ffffb04ec31e7d70 R08: ffff9df94ca85780 R09: 0000000080aa0072 [ 293.843909] R10: ffff9df94ca85700 R11: ffff9df94e1ccf58 R12: ffff9df947db2e00 [ 293.845594] R13: ffff9df947db2ed0 R14: ffff9df947db2eb8 R15: ffff9df947db2eb8 [ 293.847855] FS: 00007f5a97379800(0000) GS:ffff9dfa77c00000(0000) knlGS:0000000000000000 [ 293.850647] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 293.852940] CR2: 00007f5a97528730 CR3: 000000010bc76005 CR4: 0000000000370ef0 [ 293.854680] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 293.856423] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 293.858380] Call Trace: [ 293.859302] <TASK> [ 293.860311] ? ttwu_do_wakeup+0x1c/0x170 [ 293.861800] ? ttwu_do_activate+0x6d/0xb0 [ 293.863057] ? _raw_spin_unlock_irqrestore+0x29/0x40 [ 293.864411] ? try_to_wake_up+0x9d/0x5e0 [ 293.865618] ? debug_smp_processor_id+0x17/0x20 [ 293.866934] ? debug_smp_processor_id+0x17/0x20 [ 293.868223] ? free_unref_page+0xbf/0x120 [ 293.869470] ? __free_slab+0xcb/0x1c0 [ 293.870614] ? preempt_count_add+0x7a/0xc0 [ 293.871811] ? __slab_free+0xa0/0x2d0 [ 293.872918] ? __wake_up_common_lock+0x8a/0xc0 [ 293.874186] ? __slab_free+0xa0/0x2d0 [ 293.875305] ? free_inode_nonrcu+0x20/0x20 [ 293.876466] ? free_inode_nonrcu+0x20/0x20 [ 293.877650] ? debug_smp_processor_id+0x17/0x20 [ 293.878949] ? call_rcu+0x11a/0x240 [ 293.880060] ? f2fs_destroy_stats+0x59/0x60 [f2fs] [ 293.881437] ? kfree+0x1fe/0x230 [ 293.882674] f2fs_put_super+0x160/0x390 [f2fs] [ 293.883978] generic_shutdown_super+0x7a/0x120 [ 293.885274] kill_block_super+0x27/0x50 [ 293.886496] kill_f2fs_super+0x7f/0x100 [f2fs] [ 293.887806] deactivate_locked_super+0x35/0xa0 [ 293.889271] deactivate_super+0x40/0x50 [ 293.890513] cleanup_mnt+0x139/0x190 [ 293.891689] __cleanup_mnt+0x12/0x20 [ 293.892850] task_work_run+0x64/0xa0 [ 293.894035] exit_to_user_mode_prepare+0x1b7/ ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: media: ti-vpe: cal: Fix a NULL pointer dereference in cal_ctx_v4l2_init_formats() In cal_ctx_v4l2_init_formats(), devm_kzalloc() is assigned to ctx->active_fmt and there is a dereference of it after that, which could lead to NULL pointer dereference on failure of devm_kzalloc(). Fix this bug by adding a NULL check of ctx->active_fmt. This bug was found by a static analyzer. Builds with 'make allyesconfig' show no new warnings, and our static analyzer no longer warns about this code.Show less

In the Linux kernel, the following vulnerability has been resolved: ASoC: codecs: rx-macro: fix accessing array out of bounds for enum type Accessing enums using integer would result in array out of bounds access on platforms like aarch64 where sizeof(long) is 8 compared to enum size which is 4 bytes.Show less

In the Linux kernel, the following vulnerability has been resolved: ASoC: codecs: va-macro: fix accessing array out of bounds for enum type Accessing enums using integer would result in array out of bounds access on platforms like aarch64 where sizeof(long) is 8 compared to enum size which is 4 bytes.Show less

In the Linux kernel, the following vulnerability has been resolved: ASoC: codecs: rx-macro: fix accessing compander for aux AUX interpolator does not have compander, so check before accessing compander data for this. Without this checkan array of out bounds access will be made in comp_enabled[] array.Show less

In the Linux kernel, the following vulnerability has been resolved: ASoC: codecs: wc938x: fix accessing array out of bounds for enum type Accessing enums using integer would result in array out of bounds access on platforms like aarch64 where sizeof(long) is 8 compared to enum size which is 4 bytes. Fix this by using enumerated items instead of integers.Show less

In the Linux kernel, the following vulnerability has been resolved: ALSA: firewire-lib: fix uninitialized flag for AV/C deferred transaction AV/C deferred transaction was supported at a commit 00a7bb81c20f ("ALSA: firewire-lib: Add support for deferred transaction") while 'deferrable' flag can be uninitialized for non-control/notify AV/C transactions. UBSAN reports it: kernel: ================================================================================ kernel: UBSAN: invalid-load in /build/linux-aa0B4d/linux-5.15.0/sound/firewire/fcp.c:363:9 kernel: load of value 158 is not a valid value for type '_Bool' kernel: CPU: 3 PID: 182227 Comm: irq/35-firewire Tainted: P OE 5.15.0-18-generic #18-Ubuntu kernel: Hardware name: Gigabyte Technology Co., Ltd. AX370-Gaming 5/AX370-Gaming 5, BIOS F42b 08/01/2019 kernel: Call Trace: kernel: <IRQ> kernel: show_stack+0x52/0x58 kernel: dump_stack_lvl+0x4a/0x5f kernel: dump_stack+0x10/0x12 kernel: ubsan_epilogue+0x9/0x45 kernel: __ubsan_handle_load_invalid_value.cold+0x44/0x49 kernel: fcp_response.part.0.cold+0x1a/0x2b [snd_firewire_lib] kernel: fcp_response+0x28/0x30 [snd_firewire_lib] kernel: fw_core_handle_request+0x230/0x3d0 [firewire_core] kernel: handle_ar_packet+0x1d9/0x200 [firewire_ohci] kernel: ? handle_ar_packet+0x1d9/0x200 [firewire_ohci] kernel: ? transmit_complete_callback+0x9f/0x120 [firewire_core] kernel: ar_context_tasklet+0xa8/0x2e0 [firewire_ohci] kernel: tasklet_action_common.constprop.0+0xea/0xf0 kernel: tasklet_action+0x22/0x30 kernel: __do_softirq+0xd9/0x2e3 kernel: ? irq_finalize_oneshot.part.0+0xf0/0xf0 kernel: do_softirq+0x75/0xa0 kernel: </IRQ> kernel: <TASK> kernel: __local_bh_enable_ip+0x50/0x60 kernel: irq_forced_thread_fn+0x7e/0x90 kernel: irq_thread+0xba/0x190 kernel: ? irq_thread_fn+0x60/0x60 kernel: kthread+0x11e/0x140 kernel: ? irq_thread_check_affinity+0xf0/0xf0 kernel: ? set_kthread_struct+0x50/0x50 kernel: ret_from_fork+0x22/0x30 kernel: </TASK> kernel: ================================================================================ This commit fixes the bug. The bug has no disadvantage for the non- control/notify AV/C transactions since the flag has an effect for AV/C response with INTERIM (0x0f) status which is not used for the transactions in AV/C general specification.Show less

In the Linux kernel, the following vulnerability has been resolved: media: stk1160: If start stream fails, return buffers with VB2_BUF_STATE_QUEUED If the callback 'start_streaming' fails, then all queued buffers in the driver should be returned with state 'VB2_BUF_STATE_QUEUED'. Currently, they are returned with 'VB2_BUF_STATE_ERROR' which is wrong. Fix this. This also fixes the warning: [ 65.583633] WARNING: CPU: 5 PID: 593 at drivers/media/common/videobuf2/videobuf2-core.c:1612 vb2_start_streaming+0xd4/0x160 [videobuf2_common] [ 65.585027] Modules linked in: snd_usb_audio snd_hwdep snd_usbmidi_lib snd_rawmidi snd_soc_hdmi_codec dw_hdmi_i2s_audio saa7115 stk1160 videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common videodev mc crct10dif_ce panfrost snd_soc_simple_card snd_soc_audio_graph_card snd_soc_spdif_tx snd_soc_simple_card_utils gpu_sched phy_rockchip_pcie snd_soc_rockchip_i2s rockchipdrm analogix_dp dw_mipi_dsi dw_hdmi cec drm_kms_helper drm rtc_rk808 rockchip_saradc industrialio_triggered_buffer kfifo_buf rockchip_thermal pcie_rockchip_host ip_tables x_tables ipv6 [ 65.589383] CPU: 5 PID: 593 Comm: v4l2src0:src Tainted: G W 5.16.0-rc4-62408-g32447129cb30-dirty #14 [ 65.590293] Hardware name: Radxa ROCK Pi 4B (DT) [ 65.590696] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 65.591304] pc : vb2_start_streaming+0xd4/0x160 [videobuf2_common] [ 65.591850] lr : vb2_start_streaming+0x6c/0x160 [videobuf2_common] [ 65.592395] sp : ffff800012bc3ad0 [ 65.592685] x29: ffff800012bc3ad0 x28: 0000000000000000 x27: ffff800012bc3cd8 [ 65.593312] x26: 0000000000000000 x25: ffff00000d8a7800 x24: 0000000040045612 [ 65.593938] x23: ffff800011323000 x22: ffff800012bc3cd8 x21: ffff00000908a8b0 [ 65.594562] x20: ffff00000908a8c8 x19: 00000000fffffff4 x18: ffffffffffffffff [ 65.595188] x17: 000000040044ffff x16: 00400034b5503510 x15: ffff800011323f78 [ 65.595813] x14: ffff000013163886 x13: ffff000013163885 x12: 00000000000002ce [ 65.596439] x11: 0000000000000028 x10: 0000000000000001 x9 : 0000000000000228 [ 65.597064] x8 : 0101010101010101 x7 : 7f7f7f7f7f7f7f7f x6 : fefefeff726c5e78 [ 65.597690] x5 : ffff800012bc3990 x4 : 0000000000000000 x3 : ffff000009a34880 [ 65.598315] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff000007cd99f0 [ 65.598940] Call trace: [ 65.599155] vb2_start_streaming+0xd4/0x160 [videobuf2_common] [ 65.599672] vb2_core_streamon+0x17c/0x1a8 [videobuf2_common] [ 65.600179] vb2_streamon+0x54/0x88 [videobuf2_v4l2] [ 65.600619] vb2_ioctl_streamon+0x54/0x60 [videobuf2_v4l2] [ 65.601103] v4l_streamon+0x3c/0x50 [videodev] [ 65.601521] __video_do_ioctl+0x1a4/0x428 [videodev] [ 65.601977] video_usercopy+0x320/0x828 [videodev] [ 65.602419] video_ioctl2+0x3c/0x58 [videodev] [ 65.602830] v4l2_ioctl+0x60/0x90 [videodev] [ 65.603227] __arm64_sys_ioctl+0xa8/0xe0 [ 65.603576] invoke_syscall+0x54/0x118 [ 65.603911] el0_svc_common.constprop.3+0x84/0x100 [ 65.604332] do_el0_svc+0x34/0xa0 [ 65.604625] el0_svc+0x1c/0x50 [ 65.604897] el0t_64_sync_handler+0x88/0xb0 [ 65.605264] el0t_64_sync+0x16c/0x170 [ 65.605587] ---[ end trace 578e0ba07742170d ]---Show less

In the Linux kernel, the following vulnerability has been resolved: ASoC: atmel: Fix error handling in snd_proto_probe The device_node pointer is returned by of_parse_phandle() with refcount incremented. We should use of_node_put() on it when done. This function only calls of_node_put() in the regular path. And it will cause refcount leak in error paths. Fix this by calling of_node_put() in error handling too.Show less

In the Linux kernel, the following vulnerability has been resolved: ASoC: rockchip: Fix PM usage reference of rockchip_i2s_tdm_resume pm_runtime_get_sync will increment pm usage counter even it failed. Forgetting to putting operation will result in reference leak here. We fix it by replacing it with pm_runtime_resume_and_get to keep usage counter balanced.Show less

In the Linux kernel, the following vulnerability has been resolved: ASoC: mediatek: mt8192-mt6359: Fix error handling in mt8192_mt6359_dev_probe The device_node pointer is returned by of_parse_phandle() with refcount incremented. We should use of_node_put() on it when done. This function only calls of_node_put() in the regular path. And it will cause refcount leak in error paths. Fix this by calling of_node_put() in error handling too.Show less

In the Linux kernel, the following vulnerability has been resolved: ASoC: atmel: Add missing of_node_put() in at91sam9g20ek_audio_probe This node pointer is returned by of_parse_phandle() with refcount incremented in this function. Calling of_node_put() to avoid the refcount leak.Show less

In the Linux kernel, the following vulnerability has been resolved: ASoC: mxs: Fix error handling in mxs_sgtl5000_probe This function only calls of_node_put() in the regular path. And it will cause refcount leak in error paths. For example, when codec_np is NULL, saif_np[0] and saif_np[1] are not NULL, it will cause leaks. of_node_put() will check if the node pointer is NULL, so we can call it directly to release the refcount of regular pointers.Show less

In the Linux kernel, the following vulnerability has been resolved: ASoC: atmel: Fix error handling in sam9x5_wm8731_driver_probe The device_node pointer is returned by of_parse_phandle() with refcount incremented. We should use of_node_put() on it when done. This function only calls of_node_put() in the regular path. And it will cause refcount leak in error path.Show less

In the Linux kernel, the following vulnerability has been resolved: ASoC: mediatek: mt8195: Fix error handling in mt8195_mt6359_rt1019_rt5682_dev_probe The device_node pointer is returned by of_parse_phandle() with refcount incremented. We should use of_node_put() on it when done. This function only calls of_node_put() in the regular path. And it will cause refcount leak in error path.Show less

In the Linux kernel, the following vulnerability has been resolved: ASoC: codecs: wcd934x: Add missing of_node_put() in wcd934x_codec_parse_data The device_node pointer is returned by of_parse_phandle() with refcount incremented. We should use of_node_put() on it when done. This is similar to commit 64b92de9603f ("ASoC: wcd9335: fix a leaked reference by adding missing of_node_put")Show less

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---Show less

In the Linux kernel, the following vulnerability has been resolved: ath11k: add missing of_node_put() to avoid leak The node pointer is returned by of_find_node_by_type() or of_parse_phandle() with refcount incremented. Calling of_node_put() to aovid the refcount leak.Show less

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.Show less