In the Linux kernel, the following vulnerability has been resolved: skmsg: Skip zero length skb in sk_msg_recvmsg When running BPF selftests (./test_progs -t sockmap_basic) on a Loongarch platform, the following kernel panic occurs: [...] Oops[#1]: CPU: 22 PID: 2824 Comm: test_progs Tainted: G OE 6.10.0-rc2+ #18 Hardware name: LOONGSON Dabieshan/Loongson-TC542F0, BIOS Loongson-UDK2018 ... ... ra: 90000000048bf6c0 sk_msg_recvmsg+0x120/0x560 ERA: 9000000004162774 copy_page_to_iter+0x74/0x1c0 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) PRMD: 0000000c (PPLV0 +PIE +PWE) EUEN: 00000007 (+FPE +SXE +ASXE -BTE) ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7) ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0) BADV: 0000000000000040 PRID: 0014c011 (Loongson-64bit, Loongson-3C5000) Modules linked in: bpf_testmod(OE) xt_CHECKSUM xt_MASQUERADE xt_conntrack Process test_progs (pid: 2824, threadinfo=0000000000863a31, task=...) Stack : ... Call Trace: [<9000000004162774>] copy_page_to_iter+0x74/0x1c0 [<90000000048bf6c0>] sk_msg_recvmsg+0x120/0x560 [<90000000049f2b90>] tcp_bpf_recvmsg_parser+0x170/0x4e0 [<90000000049aae34>] inet_recvmsg+0x54/0x100 [<900000000481ad5c>] sock_recvmsg+0x7c/0xe0 [<900000000481e1a8>] __sys_recvfrom+0x108/0x1c0 [<900000000481e27c>] sys_recvfrom+0x1c/0x40 [<9000000004c076ec>] do_syscall+0x8c/0xc0 [<9000000003731da4>] handle_syscall+0xc4/0x160 Code: ... ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: Fatal exception Kernel relocated by 0x3510000 .text @ 0x9000000003710000 .data @ 0x9000000004d70000 .bss @ 0x9000000006469400 ---[ end Kernel panic - not syncing: Fatal exception ]--- [...] This crash happens every time when running sockmap_skb_verdict_shutdown subtest in sockmap_basic. This crash is because a NULL pointer is passed to page_address() in the sk_msg_recvmsg(). Due to the different implementations depending on the architecture, page_address(NULL) will trigger a panic on Loongarch platform but not on x86 platform. So this bug was hidden on x86 platform for a while, but now it is exposed on Loongarch platform. The root cause is that a zero length skb (skb->len == 0) was put on the queue. This zero length skb is a TCP FIN packet, which was sent by shutdown(), invoked in test_sockmap_skb_verdict_shutdown(): shutdown(p1, SHUT_WR); In this case, in sk_psock_skb_ingress_enqueue(), num_sge is zero, and no page is put to this sge (see sg_set_page in sg_set_page), but this empty sge is queued into ingress_msg list. And in sk_msg_recvmsg(), this empty sge is used, and a NULL page is got by sg_page(sge). Pass this NULL page to copy_page_to_iter(), which passes it to kmap_local_page() and to page_address(), then kernel panics. To solve this, we should skip this zero length skb. So in sk_msg_recvmsg(), if copy is zero, that means it's a zero length skb, skip invoking copy_page_to_iter(). We are using the EFAULT return triggered by copy_page_to_iter to check for is_fin in tcp_bpf.c.

In the Linux kernel, the following vulnerability has been resolved: f2fs: check discard support for conventional zones As the helper function f2fs_bdev_support_discard() shows, f2fs checks if the target block devices support discard by calling bdev_max_discard_sectors() and bdev_is_zoned(). This check works well for most cases, but it does not work for conventional zones on zoned block devices. F2fs assumes that zoned block devices support discard, and calls __submit_discard_cmd(). When __submit_discard_cmd() is called for sequential write required zones, it works fine since __submit_discard_cmd() issues zone reset commands instead of discard commands. However, when __submit_discard_cmd() is called for conventional zones, __blkdev_issue_discard() is called even when the devices do not support discard. The inappropriate __blkdev_issue_discard() call was not a problem before the commit 30f1e7241422 ("block: move discard checks into the ioctl handler") because __blkdev_issue_discard() checked if the target devices support discard or not. If not, it returned EOPNOTSUPP. After the commit, __blkdev_issue_discard() no longer checks it. It always returns zero and sets NULL to the given bio pointer. This NULL pointer triggers f2fs_bug_on() in __submit_discard_cmd(). The BUG is recreated with the commands below at the umount step, where /dev/nullb0 is a zoned null_blk with 5GB total size, 128MB zone size and 10 conventional zones. $ mkfs.f2fs -f -m /dev/nullb0 $ mount /dev/nullb0 /mnt $ for ((i=0;i<5;i++)); do dd if=/dev/zero of=/mnt/test bs=65536 count=1600 conv=fsync; done $ umount /mnt To fix the BUG, avoid the inappropriate __blkdev_issue_discard() call. When discard is requested for conventional zones, check if the device supports discard or not. If not, return EOPNOTSUPP.

In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix NULL pointer dereference in ocfs2_journal_dirty() bdev->bd_super has been removed and commit 8887b94d9322 change the usage from bdev->bd_super to b_assoc_map->host->i_sb. This introduces the following NULL pointer dereference in ocfs2_journal_dirty() since b_assoc_map is still not initialized. This can be easily reproduced by running xfstests generic/186, which simulate no more credits. [ 134.351592] BUG: kernel NULL pointer dereference, address: 0000000000000000 ... [ 134.355341] RIP: 0010:ocfs2_journal_dirty+0x14f/0x160 [ocfs2] ... [ 134.365071] Call Trace: [ 134.365312] <TASK> [ 134.365524] ? __die_body+0x1e/0x60 [ 134.365868] ? page_fault_oops+0x13d/0x4f0 [ 134.366265] ? __pfx_bit_wait_io+0x10/0x10 [ 134.366659] ? schedule+0x27/0xb0 [ 134.366981] ? exc_page_fault+0x6a/0x140 [ 134.367356] ? asm_exc_page_fault+0x26/0x30 [ 134.367762] ? ocfs2_journal_dirty+0x14f/0x160 [ocfs2] [ 134.368305] ? ocfs2_journal_dirty+0x13d/0x160 [ocfs2] [ 134.368837] ocfs2_create_new_meta_bhs.isra.51+0x139/0x2e0 [ocfs2] [ 134.369454] ocfs2_grow_tree+0x688/0x8a0 [ocfs2] [ 134.369927] ocfs2_split_and_insert.isra.67+0x35c/0x4a0 [ocfs2] [ 134.370521] ocfs2_split_extent+0x314/0x4d0 [ocfs2] [ 134.371019] ocfs2_change_extent_flag+0x174/0x410 [ocfs2] [ 134.371566] ocfs2_add_refcount_flag+0x3fa/0x630 [ocfs2] [ 134.372117] ocfs2_reflink_remap_extent+0x21b/0x4c0 [ocfs2] [ 134.372994] ? inode_update_timestamps+0x4a/0x120 [ 134.373692] ? __pfx_ocfs2_journal_access_di+0x10/0x10 [ocfs2] [ 134.374545] ? __pfx_ocfs2_journal_access_di+0x10/0x10 [ocfs2] [ 134.375393] ocfs2_reflink_remap_blocks+0xe4/0x4e0 [ocfs2] [ 134.376197] ocfs2_remap_file_range+0x1de/0x390 [ocfs2] [ 134.376971] ? security_file_permission+0x29/0x50 [ 134.377644] vfs_clone_file_range+0xfe/0x320 [ 134.378268] ioctl_file_clone+0x45/0xa0 [ 134.378853] do_vfs_ioctl+0x457/0x990 [ 134.379422] __x64_sys_ioctl+0x6e/0xd0 [ 134.379987] do_syscall_64+0x5d/0x170 [ 134.380550] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 134.381231] RIP: 0033:0x7fa4926397cb [ 134.381786] Code: 73 01 c3 48 8b 0d bd 56 38 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 8d 56 38 00 f7 d8 64 89 01 48 [ 134.383930] RSP: 002b:00007ffc2b39f7b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 134.384854] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fa4926397cb [ 134.385734] RDX: 00007ffc2b39f7f0 RSI: 000000004020940d RDI: 0000000000000003 [ 134.386606] RBP: 0000000000000000 R08: 00111a82a4f015bb R09: 00007fa494221000 [ 134.387476] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 134.388342] R13: 0000000000f10000 R14: 0000558e844e2ac8 R15: 0000000000f10000 [ 134.389207] </TASK> Fix it by only aborting transaction and journal in ocfs2_journal_dirty() now, and leave ocfs2_abort() later when detecting an aborted handle, e.g. start next transaction. Also log the handle details in this case.

In the Linux kernel, the following vulnerability has been resolved: media: hantro: Check whether reset op is defined before use The i.MX8MM/N/P does not define the .reset op since reset of the VPU is done by genpd. Check whether the .reset op is defined before calling it to avoid NULL pointer dereference. Note that the Fixes tag is set to the commit which removed the reset op from i.MX8M Hantro G2 implementation, this is because before this commit all the implementations did define the .reset op.

In the Linux kernel, the following vulnerability has been resolved: Add exception protection processing for vd in axi_chan_handle_err function Since there is no protection for vd, a kernel panic will be triggered here in exceptional cases. You can refer to the processing of axi_chan_block_xfer_complete function The triggered kernel panic is as follows: [ 67.848444] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000060 [ 67.848447] Mem abort info: [ 67.848449] ESR = 0x96000004 [ 67.848451] EC = 0x25: DABT (current EL), IL = 32 bits [ 67.848454] SET = 0, FnV = 0 [ 67.848456] EA = 0, S1PTW = 0 [ 67.848458] Data abort info: [ 67.848460] ISV = 0, ISS = 0x00000004 [ 67.848462] CM = 0, WnR = 0 [ 67.848465] user pgtable: 4k pages, 48-bit VAs, pgdp=00000800c4c0b000 [ 67.848468] [0000000000000060] pgd=0000000000000000, p4d=0000000000000000 [ 67.848472] Internal error: Oops: 96000004 [#1] SMP [ 67.848475] Modules linked in: dmatest [ 67.848479] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.10.100-emu_x2rc+ #11 [ 67.848483] pstate: 62000085 (nZCv daIf -PAN -UAO +TCO BTYPE=--) [ 67.848487] pc : axi_chan_handle_err+0xc4/0x230 [ 67.848491] lr : axi_chan_handle_err+0x30/0x230 [ 67.848493] sp : ffff0803fe55ae50 [ 67.848495] x29: ffff0803fe55ae50 x28: ffff800011212200 [ 67.848500] x27: ffff0800c42c0080 x26: ffff0800c097c080 [ 67.848504] x25: ffff800010d33880 x24: ffff80001139d850 [ 67.848508] x23: ffff0800c097c168 x22: 0000000000000000 [ 67.848512] x21: 0000000000000080 x20: 0000000000002000 [ 67.848517] x19: ffff0800c097c080 x18: 0000000000000000 [ 67.848521] x17: 0000000000000000 x16: 0000000000000000 [ 67.848525] x15: 0000000000000000 x14: 0000000000000000 [ 67.848529] x13: 0000000000000000 x12: 0000000000000040 [ 67.848533] x11: ffff0800c0400248 x10: ffff0800c040024a [ 67.848538] x9 : ffff800010576cd4 x8 : ffff0800c0400270 [ 67.848542] x7 : 0000000000000000 x6 : ffff0800c04003e0 [ 67.848546] x5 : ffff0800c0400248 x4 : ffff0800c4294480 [ 67.848550] x3 : dead000000000100 x2 : dead000000000122 [ 67.848555] x1 : 0000000000000100 x0 : ffff0800c097c168 [ 67.848559] Call trace: [ 67.848562] axi_chan_handle_err+0xc4/0x230 [ 67.848566] dw_axi_dma_interrupt+0xf4/0x590 [ 67.848569] __handle_irq_event_percpu+0x60/0x220 [ 67.848573] handle_irq_event+0x64/0x120 [ 67.848576] handle_fasteoi_irq+0xc4/0x220 [ 67.848580] __handle_domain_irq+0x80/0xe0 [ 67.848583] gic_handle_irq+0xc0/0x138 [ 67.848585] el1_irq+0xc8/0x180 [ 67.848588] arch_cpu_idle+0x14/0x2c [ 67.848591] default_idle_call+0x40/0x16c [ 67.848594] do_idle+0x1f0/0x250 [ 67.848597] cpu_startup_entry+0x2c/0x60 [ 67.848600] rest_init+0xc0/0xcc [ 67.848603] arch_call_rest_init+0x14/0x1c [ 67.848606] start_kernel+0x4cc/0x500 [ 67.848610] Code: eb0002ff 9a9f12d6 f2fbd5a2 f2fbd5a3 (a94602c1) [ 67.848613] ---[ end trace 585a97036f88203a ]---

In the Linux kernel, the following vulnerability has been resolved: vfio/mdev: Fix a null-ptr-deref bug for mdev_unregister_parent() Inject fault while probing mdpy.ko, if kstrdup() of create_dir() fails in kobject_add_internal() in kobject_init_and_add() in mdev_type_add() in parent_create_sysfs_files(), it will return 0 and probe successfully. And when rmmod mdpy.ko, the mdpy_dev_exit() will call mdev_unregister_parent(), the mdev_type_remove() may traverse uninitialized parent->types[i] in parent_remove_sysfs_files(), and it will cause below null-ptr-deref. If mdev_type_add() fails, return the error code and kset_unregister() to fix the issue. general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 2 PID: 10215 Comm: rmmod Tainted: G W N 6.6.0-rc2+ #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:__kobject_del+0x62/0x1c0 Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 51 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 28 48 8d 7d 10 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 24 01 00 00 48 8b 75 10 48 89 df 48 8d 6b 3c e8 RSP: 0018:ffff88810695fd30 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffffffffa0270268 RCX: 0000000000000000 RDX: 0000000000000002 RSI: 0000000000000004 RDI: 0000000000000010 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10233a4ef1 R10: ffff888119d2778b R11: 0000000063666572 R12: 0000000000000000 R13: fffffbfff404e2d4 R14: dffffc0000000000 R15: ffffffffa0271660 FS: 00007fbc81981540(0000) GS:ffff888119d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc14a142dc0 CR3: 0000000110a62003 CR4: 0000000000770ee0 DR0: ffffffff8fb0bce8 DR1: ffffffff8fb0bce9 DR2: ffffffff8fb0bcea DR3: ffffffff8fb0bceb DR6: 00000000fffe0ff0 DR7: 0000000000000600 PKRU: 55555554 Call Trace: <TASK> ? die_addr+0x3d/0xa0 ? exc_general_protection+0x144/0x220 ? asm_exc_general_protection+0x22/0x30 ? __kobject_del+0x62/0x1c0 kobject_del+0x32/0x50 parent_remove_sysfs_files+0xd6/0x170 [mdev] mdev_unregister_parent+0xfb/0x190 [mdev] ? mdev_register_parent+0x270/0x270 [mdev] ? find_module_all+0x9d/0xe0 mdpy_dev_exit+0x17/0x63 [mdpy] __do_sys_delete_module.constprop.0+0x2fa/0x4b0 ? module_flags+0x300/0x300 ? __fput+0x4e7/0xa00 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7fbc813221b7 Code: 73 01 c3 48 8b 0d d1 8c 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 8c 2c 00 f7 d8 64 89 01 48 RSP: 002b:00007ffe780e0648 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 RAX: ffffffffffffffda RBX: 00007ffe780e06a8 RCX: 00007fbc813221b7 RDX: 000000000000000a RSI: 0000000000000800 RDI: 000055e214df9b58 RBP: 000055e214df9af0 R08: 00007ffe780df5c1 R09: 0000000000000000 R10: 00007fbc8139ecc0 R11: 0000000000000206 R12: 00007ffe780e0870 R13: 00007ffe780e0ed0 R14: 000055e214df9260 R15: 000055e214df9af0 </TASK> Modules linked in: mdpy(-) mdev vfio_iommu_type1 vfio [last unloaded: mdpy] Dumping ftrace buffer: (ftrace buffer empty) ---[ end trace 0000000000000000 ]--- RIP: 0010:__kobject_del+0x62/0x1c0 Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 51 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 28 48 8d 7d 10 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 24 01 00 00 48 8b 75 10 48 89 df 48 8d 6b 3c e8 RSP: 0018:ffff88810695fd30 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffffffffa0270268 RCX: 0000000000000000 RDX: 0000000000000002 RSI: 0000000000000004 RDI: 0000000000000010 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10233a4ef1 R10: ffff888119d2778b R11: 0000000063666572 R12: 0000000000000000 R13: fffffbfff404e2d4 R14: dffffc0000000000 R15: ffffffffa0271660 FS: 00007fbc81981540(0000) GS:ffff888119d00000(000 ---truncated---

In the Linux kernel, the following vulnerability has been resolved: clk: mediatek: clk-mt6797: Add check for mtk_alloc_clk_data Add the check for the return value of mtk_alloc_clk_data() in order to avoid NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btusb: Add date->evt_skb is NULL check fix crash because of null pointers [ 6104.969662] BUG: kernel NULL pointer dereference, address: 00000000000000c8 [ 6104.969667] #PF: supervisor read access in kernel mode [ 6104.969668] #PF: error_code(0x0000) - not-present page [ 6104.969670] PGD 0 P4D 0 [ 6104.969673] Oops: 0000 [#1] SMP NOPTI [ 6104.969684] RIP: 0010:btusb_mtk_hci_wmt_sync+0x144/0x220 [btusb] [ 6104.969688] RSP: 0018:ffffb8d681533d48 EFLAGS: 00010246 [ 6104.969689] RAX: 0000000000000000 RBX: ffff8ad560bb2000 RCX: 0000000000000006 [ 6104.969691] RDX: 0000000000000000 RSI: ffffb8d681533d08 RDI: 0000000000000000 [ 6104.969692] RBP: ffffb8d681533d70 R08: 0000000000000001 R09: 0000000000000001 [ 6104.969694] R10: 0000000000000001 R11: 00000000fa83b2da R12: ffff8ad461d1d7c0 [ 6104.969695] R13: 0000000000000000 R14: ffff8ad459618c18 R15: ffffb8d681533d90 [ 6104.969697] FS: 00007f5a1cab9d40(0000) GS:ffff8ad578200000(0000) knlGS:00000 [ 6104.969699] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6104.969700] CR2: 00000000000000c8 CR3: 000000018620c001 CR4: 0000000000760ef0 [ 6104.969701] PKRU: 55555554 [ 6104.969702] Call Trace: [ 6104.969708] btusb_mtk_shutdown+0x44/0x80 [btusb] [ 6104.969732] hci_dev_do_close+0x470/0x5c0 [bluetooth] [ 6104.969748] hci_rfkill_set_block+0x56/0xa0 [bluetooth] [ 6104.969753] rfkill_set_block+0x92/0x160 [ 6104.969755] rfkill_fop_write+0x136/0x1e0 [ 6104.969759] __vfs_write+0x18/0x40 [ 6104.969761] vfs_write+0xdf/0x1c0 [ 6104.969763] ksys_write+0xb1/0xe0 [ 6104.969765] __x64_sys_write+0x1a/0x20 [ 6104.969769] do_syscall_64+0x51/0x180 [ 6104.969771] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 6104.969773] RIP: 0033:0x7f5a21f18fef [ 6104.9] RSP: 002b:00007ffeefe39010 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 [ 6104.969780] RAX: ffffffffffffffda RBX: 000055c10a7560a0 RCX: 00007f5a21f18fef [ 6104.969781] RDX: 0000000000000008 RSI: 00007ffeefe39060 RDI: 0000000000000012 [ 6104.969782] RBP: 00007ffeefe39060 R08: 0000000000000000 R09: 0000000000000017 [ 6104.969784] R10: 00007ffeefe38d97 R11: 0000000000000293 R12: 0000000000000002 [ 6104.969785] R13: 00007ffeefe39220 R14: 00007ffeefe391a0 R15: 000055c10a72acf0

In the Linux kernel, the following vulnerability has been resolved: apparmor: avoid crash when parsed profile name is empty When processing a packed profile in unpack_profile() described like "profile :ns::samba-dcerpcd /usr/lib*/samba/{,samba/}samba-dcerpcd {...}" a string ":samba-dcerpcd" is unpacked as a fully-qualified name and then passed to aa_splitn_fqname(). aa_splitn_fqname() treats ":samba-dcerpcd" as only containing a namespace. Thus it returns NULL for tmpname, meanwhile tmpns is non-NULL. Later aa_alloc_profile() crashes as the new profile name is NULL now. general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 6 PID: 1657 Comm: apparmor_parser Not tainted 6.7.0-rc2-dirty #16 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014 RIP: 0010:strlen+0x1e/0xa0 Call Trace: <TASK> ? strlen+0x1e/0xa0 aa_policy_init+0x1bb/0x230 aa_alloc_profile+0xb1/0x480 unpack_profile+0x3bc/0x4960 aa_unpack+0x309/0x15e0 aa_replace_profiles+0x213/0x33c0 policy_update+0x261/0x370 profile_replace+0x20e/0x2a0 vfs_write+0x2af/0xe00 ksys_write+0x126/0x250 do_syscall_64+0x46/0xf0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 </TASK> ---[ end trace 0000000000000000 ]--- RIP: 0010:strlen+0x1e/0xa0 It seems such behaviour of aa_splitn_fqname() is expected and checked in other places where it is called (e.g. aa_remove_profiles). Well, there is an explicit comment "a ns name without a following profile is allowed" inside. AFAICS, nothing can prevent unpacked "name" to be in form like ":samba-dcerpcd" - it is passed from userspace. Deny the whole profile set replacement in such case and inform user with EPROTO and an explaining message. Found by Linux Verification Center (linuxtesting.org).

In the Linux kernel, the following vulnerability has been resolved: net: fix NULL pointer in skb_segment_list Commit 3a1296a38d0c ("net: Support GRO/GSO fraglist chaining.") introduced UDP listifyed GRO. The segmentation relies on frag_list being untouched when passing through the network stack. This assumption can be broken sometimes, where frag_list itself gets pulled into linear area, leaving frag_list being NULL. When this happens it can trigger following NULL pointer dereference, and panic the kernel. Reverse the test condition should fix it. [19185.577801][ C1] BUG: kernel NULL pointer dereference, address: ... [19185.663775][ C1] RIP: 0010:skb_segment_list+0x1cc/0x390 ... [19185.834644][ C1] Call Trace: [19185.841730][ C1] <TASK> [19185.848563][ C1] __udp_gso_segment+0x33e/0x510 [19185.857370][ C1] inet_gso_segment+0x15b/0x3e0 [19185.866059][ C1] skb_mac_gso_segment+0x97/0x110 [19185.874939][ C1] __skb_gso_segment+0xb2/0x160 [19185.883646][ C1] udp_queue_rcv_skb+0xc3/0x1d0 [19185.892319][ C1] udp_unicast_rcv_skb+0x75/0x90 [19185.900979][ C1] ip_protocol_deliver_rcu+0xd2/0x200 [19185.910003][ C1] ip_local_deliver_finish+0x44/0x60 [19185.918757][ C1] __netif_receive_skb_one_core+0x8b/0xa0 [19185.927834][ C1] process_backlog+0x88/0x130 [19185.935840][ C1] __napi_poll+0x27/0x150 [19185.943447][ C1] net_rx_action+0x27e/0x5f0 [19185.951331][ C1] ? mlx5_cq_tasklet_cb+0x70/0x160 [mlx5_core] [19185.960848][ C1] __do_softirq+0xbc/0x25d [19185.968607][ C1] irq_exit_rcu+0x83/0xb0 [19185.976247][ C1] common_interrupt+0x43/0xa0 [19185.984235][ C1] asm_common_interrupt+0x22/0x40 ... [19186.094106][ C1] </TASK>

In the Linux kernel, the following vulnerability has been resolved: bpf: support non-r10 register spill/fill to/from stack in precision tracking Use instruction (jump) history to record instructions that performed register spill/fill to/from stack, regardless if this was done through read-only r10 register, or any other register after copying r10 into it *and* potentially adjusting offset. To make this work reliably, we push extra per-instruction flags into instruction history, encoding stack slot index (spi) and stack frame number in extra 10 bit flags we take away from prev_idx in instruction history. We don't touch idx field for maximum performance, as it's checked most frequently during backtracking. This change removes basically the last remaining practical limitation of precision backtracking logic in BPF verifier. It fixes known deficiencies, but also opens up new opportunities to reduce number of verified states, explored in the subsequent patches. There are only three differences in selftests' BPF object files according to veristat, all in the positive direction (less states). File Program Insns (A) Insns (B) Insns (DIFF) States (A) States (B) States (DIFF) -------------------------------------- ------------- --------- --------- ------------- ---------- ---------- ------------- test_cls_redirect_dynptr.bpf.linked3.o cls_redirect 2987 2864 -123 (-4.12%) 240 231 -9 (-3.75%) xdp_synproxy_kern.bpf.linked3.o syncookie_tc 82848 82661 -187 (-0.23%) 5107 5073 -34 (-0.67%) xdp_synproxy_kern.bpf.linked3.o syncookie_xdp 85116 84964 -152 (-0.18%) 5162 5130 -32 (-0.62%) Note, I avoided renaming jmp_history to more generic insn_hist to minimize number of lines changed and potential merge conflicts between bpf and bpf-next trees. Notice also cur_hist_entry pointer reset to NULL at the beginning of instruction verification loop. This pointer avoids the problem of relying on last jump history entry's insn_idx to determine whether we already have entry for current instruction or not. It can happen that we added jump history entry because current instruction is_jmp_point(), but also we need to add instruction flags for stack access. In this case, we don't want to entries, so we need to reuse last added entry, if it is present. Relying on insn_idx comparison has the same ambiguity problem as the one that was fixed recently in [0], so we avoid that. [0] https://patchwork.kernel.org/project/netdevbpf/patch/20231110002638.4168352-3-andrii@kernel.org/

In the Linux kernel, the following vulnerability has been resolved: HID: betop: check shape of output reports betopff_init() only checks the total sum of the report counts for each report field to be at least 4, but hid_betopff_play() expects 4 report fields. A device advertising an output report with one field and 4 report counts would pass the check but crash the kernel with a NULL pointer dereference in hid_betopff_play().

In the Linux kernel, the following vulnerability has been resolved: fs: Pass AT_GETATTR_NOSEC flag to getattr interface function When vfs_getattr_nosec() calls a filesystem's getattr interface function then the 'nosec' should propagate into this function so that vfs_getattr_nosec() can again be called from the filesystem's gettattr rather than vfs_getattr(). The latter would add unnecessary security checks that the initial vfs_getattr_nosec() call wanted to avoid. Therefore, introduce the getattr flag GETATTR_NOSEC and allow to pass with the new getattr_flags parameter to the getattr interface function. In overlayfs and ecryptfs use this flag to determine which one of the two functions to call. In a recent code change introduced to IMA vfs_getattr_nosec() ended up calling vfs_getattr() in overlayfs, which in turn called security_inode_getattr() on an exiting process that did not have current->fs set anymore, which then caused a kernel NULL pointer dereference. With this change the call to security_inode_getattr() can be avoided, thus avoiding the NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: ice: Fix some null pointer dereference issues in ice_ptp.c devm_kasprintf() returns a pointer to dynamically allocated memory which can be NULL upon failure.

In the Linux kernel, the following vulnerability has been resolved: media: pci: cx23885: check cx23885_vdev_init() return cx23885_vdev_init() can return a NULL pointer, but that pointer is used in the next line without a check. Add a NULL pointer check and go to the error unwind if it is NULL.

In the Linux kernel, the following vulnerability has been resolved: squashfs: harden sanity check in squashfs_read_xattr_id_table While mounting a corrupted filesystem, a signed integer '*xattr_ids' can become less than zero. This leads to the incorrect computation of 'len' and 'indexes' values which can cause null-ptr-deref in copy_bio_to_actor() or out-of-bounds accesses in the next sanity checks inside squashfs_read_xattr_id_table(). Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

In the Linux kernel, the following vulnerability has been resolved: gfs2: Fix kernel NULL pointer dereference in gfs2_rgrp_dump Syzkaller has reported a NULL pointer dereference when accessing rgd->rd_rgl in gfs2_rgrp_dump(). This can happen when creating rgd->rd_gl fails in read_rindex_entry(). Add a NULL pointer check in gfs2_rgrp_dump() to prevent that.

In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Fix possible NULL pointer dereference in snd_usb_pcm_has_fixed_rate() The subs function argument may be NULL, so do not use it before the NULL check.

In the Linux kernel, the following vulnerability has been resolved: usb: typec: ucsi: Don't attempt to resume the ports before they exist This will fix null pointer dereference that was caused by the driver attempting to resume ports that were not yet registered.

In the Linux kernel, the following vulnerability has been resolved: power: supply: Fix null pointer dereference in smb2_probe devm_kasprintf and devm_kzalloc return a pointer to dynamically allocated memory which can be NULL upon failure.

In the Linux kernel, the following vulnerability has been resolved: mfd: syscon: Fix null pointer dereference in of_syscon_register() kasprintf() returns a pointer to dynamically allocated memory which can be NULL upon failure.

In the Linux kernel, the following vulnerability has been resolved: tty: vcc: Add check for kstrdup() in vcc_probe() Add check for the return value of kstrdup() and return the error, if it fails in order to avoid NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Fix an NULL dereference bug The issue here is when this is called from ntfs_load_attr_list(). The "size" comes from le32_to_cpu(attr->res.data_size) so it can't overflow on a 64bit systems but on 32bit systems the "+ 1023" can overflow and the result is zero. This means that the kmalloc will succeed by returning the ZERO_SIZE_PTR and then the memcpy() will crash with an Oops on the next line.

In the Linux kernel, the following vulnerability has been resolved: powerpc/mm: Fix null-pointer dereference in pgtable_cache_add kasprintf() returns a pointer to dynamically allocated memory which can be NULL upon failure. Ensure the allocation was successful by checking the pointer validity.

In the Linux kernel, the following vulnerability has been resolved: drm/tegra: dsi: Add missing check for of_find_device_by_node Add check for the return value of of_find_device_by_node() and return the error if it fails in order to avoid NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: serial: 8250_port: Check IRQ data before use In case the leaf driver wants to use IRQ polling (irq = 0) and IIR register shows that an interrupt happened in the 8250 hardware the IRQ data can be NULL. In such a case we need to skip the wake event as we came to this path from the timer interrupt and quite likely system is already awake. Without this fix we have got an Oops: serial8250: ttyS0 at I/O 0x3f8 (irq = 0, base_baud = 115200) is a 16550A ... BUG: kernel NULL pointer dereference, address: 0000000000000010 RIP: 0010:serial8250_handle_irq+0x7c/0x240 Call Trace: ? serial8250_handle_irq+0x7c/0x240 ? __pfx_serial8250_timeout+0x10/0x10

In the Linux kernel, the following vulnerability has been resolved: aio: fix mremap after fork null-deref Commit e4a0d3e720e7 ("aio: Make it possible to remap aio ring") introduced a null-deref if mremap is called on an old aio mapping after fork as mm->ioctx_table will be set to NULL. [jmoyer@redhat.com: fix 80 column issue]

In the Linux kernel, the following vulnerability has been resolved: gsmi: fix null-deref in gsmi_get_variable We can get EFI variables without fetching the attribute, so we must allow for that in gsmi. commit 859748255b43 ("efi: pstore: Omit efivars caching EFI varstore access layer") added a new get_variable call with attr=NULL, which triggers panic in gsmi.

In the Linux kernel, the following vulnerability has been resolved: RDMA/irdma: Fix potential NULL-ptr-dereference in_dev_get() can return NULL which will cause a failure once idev is dereferenced in in_dev_for_each_ifa_rtnl(). This patch adds a check for NULL value in idev beforehand. Found by Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix NULL pointer dereference at hibernate During hibernate sequence the source context might not have a clk_mgr. So don't use it to look for DML2 support.

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Add NULL ptr dereference checking at the end of attr_allocate_frame() It is preferable to exit through the out: label because internal debugging functions are located there.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/vkms: fix a possible null pointer dereference In amdgpu_vkms_conn_get_modes(), the return value of drm_cvt_mode() is assigned to mode, which will lead to a NULL pointer dereference on failure of drm_cvt_mode(). Add a check to avoid null pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: hwmon: (axi-fan-control) Fix possible NULL pointer dereference axi_fan_control_irq_handler(), dependent on the private axi_fan_control_data structure, might be called before the hwmon device is registered. That will cause an "Unable to handle kernel NULL pointer dereference" error.

In the Linux kernel, the following vulnerability has been resolved: x86/i8259: Mark legacy PIC interrupts with IRQ_LEVEL Baoquan reported that after triggering a crash the subsequent crash-kernel fails to boot about half of the time. It triggers a NULL pointer dereference in the periodic tick code. This happens because the legacy timer interrupt (IRQ0) is resent in software which happens in soft interrupt (tasklet) context. In this context get_irq_regs() returns NULL which leads to the NULL pointer dereference. The reason for the resend is a spurious APIC interrupt on the IRQ0 vector which is captured and leads to a resend when the legacy timer interrupt is enabled. This is wrong because the legacy PIC interrupts are level triggered and therefore should never be resent in software, but nothing ever sets the IRQ_LEVEL flag on those interrupts, so the core code does not know about their trigger type. Ensure that IRQ_LEVEL is set when the legacy PCI interrupts are set up.

In the Linux kernel, the following vulnerability has been resolved: drm/panel: fix a possible null pointer dereference In versatile_panel_get_modes(), the return value of drm_mode_duplicate() is assigned to mode, which will lead to a NULL pointer dereference on failure of drm_mode_duplicate(). Add a check to avoid npd.

In the Linux kernel, the following vulnerability has been resolved: clk: mediatek: clk-mt7629-eth: Add check for mtk_alloc_clk_data Add the check for the return value of mtk_alloc_clk_data() in order to avoid NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: drivers/perf: hisi: use cpuhp_state_remove_instance_nocalls() for hisi_hns3_pmu uninit process When tearing down a 'hisi_hns3' PMU, we mistakenly run the CPU hotplug callbacks after the device has been unregistered, leading to fireworks when we try to execute empty function callbacks within the driver: | Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 | CPU: 0 PID: 15 Comm: cpuhp/0 Tainted: G W O 5.12.0-rc4+ #1 | Hardware name: , BIOS KpxxxFPGA 1P B600 V143 04/22/2021 | pstate: 80400009 (Nzcv daif +PAN -UAO -TCO BTYPE=--) | pc : perf_pmu_migrate_context+0x98/0x38c | lr : perf_pmu_migrate_context+0x94/0x38c | | Call trace: | perf_pmu_migrate_context+0x98/0x38c | hisi_hns3_pmu_offline_cpu+0x104/0x12c [hisi_hns3_pmu] Use cpuhp_state_remove_instance_nocalls() instead of cpuhp_state_remove_instance() so that the notifiers don't execute after the PMU device has been unregistered. [will: Rewrote commit message]

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix potential null pointer derefernce The amdgpu_ras_get_context may return NULL if device not support ras feature, so add check before using.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix potential NULL dereference Fix potential NULL dereference, in the case when "man", the resource manager might be NULL, when/if we print debug information.

In the Linux kernel, the following vulnerability has been resolved: clk: mediatek: clk-mt2701: Add check for mtk_alloc_clk_data Add the check for the return value of mtk_alloc_clk_data() in order to avoid NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: media: vidtv: mux: Add check and kfree for kstrdup Add check for the return value of kstrdup() and return the error if it fails in order to avoid NULL pointer dereference. Moreover, use kfree() in the later error handling in order to avoid memory leak.

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_ncm: fix potential NULL ptr deref in ncm_bitrate() In Google internal bug 265639009 we've received an (as yet) unreproducible crash report from an aarch64 GKI 5.10.149-android13 running device. AFAICT the source code is at: https://android.googlesource.com/kernel/common/+/refs/tags/ASB-2022-12-05_13-5.10 The call stack is: ncm_close() -> ncm_notify() -> ncm_do_notify() with the crash at: ncm_do_notify+0x98/0x270 Code: 79000d0b b9000a6c f940012a f9400269 (b9405d4b) Which I believe disassembles to (I don't know ARM assembly, but it looks sane enough to me...): // halfword (16-bit) store presumably to event->wLength (at offset 6 of struct usb_cdc_notification) 0B 0D 00 79 strh w11, [x8, #6] // word (32-bit) store presumably to req->Length (at offset 8 of struct usb_request) 6C 0A 00 B9 str w12, [x19, #8] // x10 (NULL) was read here from offset 0 of valid pointer x9 // IMHO we're reading 'cdev->gadget' and getting NULL // gadget is indeed at offset 0 of struct usb_composite_dev 2A 01 40 F9 ldr x10, [x9] // loading req->buf pointer, which is at offset 0 of struct usb_request 69 02 40 F9 ldr x9, [x19] // x10 is null, crash, appears to be attempt to read cdev->gadget->max_speed 4B 5D 40 B9 ldr w11, [x10, #0x5c] which seems to line up with ncm_do_notify() case NCM_NOTIFY_SPEED code fragment: event->wLength = cpu_to_le16(8); req->length = NCM_STATUS_BYTECOUNT; /* SPEED_CHANGE data is up/down speeds in bits/sec */ data = req->buf + sizeof *event; data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget)); My analysis of registers and NULL ptr deref crash offset (Unable to handle kernel NULL pointer dereference at virtual address 000000000000005c) heavily suggests that the crash is due to 'cdev->gadget' being NULL when executing: data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget)); which calls: ncm_bitrate(NULL) which then calls: gadget_is_superspeed(NULL) which reads ((struct usb_gadget *)NULL)->max_speed and hits a panic. AFAICT, if I'm counting right, the offset of max_speed is indeed 0x5C. (remember there's a GKI KABI reservation of 16 bytes in struct work_struct) It's not at all clear to me how this is all supposed to work... but returning 0 seems much better than panic-ing...

In the Linux kernel, the following vulnerability has been resolved: wifi: wfx: fix possible NULL pointer dereference in wfx_set_mfp_ap() Since 'ieee80211_beacon_get()' can return NULL, 'wfx_set_mfp_ap()' should check the return value before examining skb data. So convert the latter to return an appropriate error code and propagate it to return from 'wfx_start_ap()' as well. Compile tested only.

In the Linux kernel, the following vulnerability has been resolved: clk: mediatek: clk-mt6779: Add check for mtk_alloc_clk_data Add the check for the return value of mtk_alloc_clk_data() in order to avoid NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: drm/msm: another fix for the headless Adreno GPU Fix another oops reproducible when rebooting the board with the Adreno GPU working in the headless mode (e.g. iMX platforms). Unable to handle kernel NULL pointer dereference at virtual address 00000000 when read [00000000] *pgd=74936831, *pte=00000000, *ppte=00000000 Internal error: Oops: 17 [#1] ARM CPU: 0 PID: 51 Comm: reboot Not tainted 6.2.0-rc1-dirty #11 Hardware name: Freescale i.MX53 (Device Tree Support) PC is at msm_atomic_commit_tail+0x50/0x970 LR is at commit_tail+0x9c/0x188 pc : [<c06aa430>] lr : [<c067a214>] psr: 600e0013 sp : e0851d30 ip : ee4eb7eb fp : 00090acc r10: 00000058 r9 : c2193014 r8 : c4310000 r7 : c4759380 r6 : 07bef61d r5 : 00000000 r4 : 00000000 r3 : c44cc440 r2 : 00000000 r1 : 00000000 r0 : 00000000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: 74910019 DAC: 00000051 Register r0 information: NULL pointer Register r1 information: NULL pointer Register r2 information: NULL pointer Register r3 information: slab kmalloc-1k start c44cc400 pointer offset 64 size 1024 Register r4 information: NULL pointer Register r5 information: NULL pointer Register r6 information: non-paged memory Register r7 information: slab kmalloc-128 start c4759380 pointer offset 0 size 128 Register r8 information: slab kmalloc-2k start c4310000 pointer offset 0 size 2048 Register r9 information: non-slab/vmalloc memory Register r10 information: non-paged memory Register r11 information: non-paged memory Register r12 information: non-paged memory Process reboot (pid: 51, stack limit = 0xc80046d9) Stack: (0xe0851d30 to 0xe0852000) 1d20: c4759380 fbd77200 000005ff 002b9c70 1d40: c4759380 c4759380 00000000 07bef61d 00000600 c0d6fe7c c2193014 00000058 1d60: 00090acc c067a214 00000000 c4759380 c4310000 00000000 c44cc854 c067a89c 1d80: 00000000 00000000 00000000 c4310468 00000000 c4759380 c4310000 c4310468 1da0: c4310470 c0643258 c4759380 00000000 00000000 c0c4ee24 00000000 c44cc810 1dc0: 00000000 c0c4ee24 00000000 c44cc810 00000000 0347d2a8 e0851e00 e0851e00 1de0: c4759380 c067ad20 c4310000 00000000 c44cc810 c27f8718 c44cc854 c067adb8 1e00: c4933000 00000002 00000001 00000000 00000000 c2130850 00000000 c2130854 1e20: c25fc488 00000000 c0ff162c 00000000 00000001 00000002 00000000 00000000 1e40: c43102c0 c43102c0 00000000 0347d2a8 c44cc810 c44cc814 c2133da8 c06d1a60 1e60: 00000000 00000000 00079028 c2012f24 fee1dead c4933000 00000058 c01431e4 1e80: 01234567 c0143a20 00000000 00000000 00000000 00000000 00000000 00000000 1ea0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1ec0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1ee0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f00: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f20: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f40: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1f80: 00000000 00000000 00000000 0347d2a8 00000002 00000004 00000078 00000058 1fa0: c010028c c0100060 00000002 00000004 fee1dead 28121969 01234567 00079028 1fc0: 00000002 00000004 00000078 00000058 0002fdc5 00000000 00000000 00090acc 1fe0: 00000058 becc9c64 b6e97e05 b6e0e5f6 600e0030 fee1dead 00000000 00000000 msm_atomic_commit_tail from commit_tail+0x9c/0x188 commit_tail from drm_atomic_helper_commit+0x160/0x188 drm_atomic_helper_commit from drm_atomic_commit+0xac/0xe0 drm_atomic_commit from drm_atomic_helper_disable_all+0x1b0/0x1c0 drm_atomic_helper_disable_all from drm_atomic_helper_shutdown+0x88/0x140 drm_atomic_helper_shutdown from device_shutdown+0x16c/0x240 device_shutdown from kernel_restart+0x38/0x90 kernel_restart from __do_sys_reboot+0x ---truncated---

In the Linux kernel, the following vulnerability has been resolved: tracing: Have trace_event_file have ref counters The following can crash the kernel: # cd /sys/kernel/tracing # echo 'p:sched schedule' > kprobe_events # exec 5>>events/kprobes/sched/enable # > kprobe_events # exec 5>&- The above commands: 1. Change directory to the tracefs directory 2. Create a kprobe event (doesn't matter what one) 3. Open bash file descriptor 5 on the enable file of the kprobe event 4. Delete the kprobe event (removes the files too) 5. Close the bash file descriptor 5 The above causes a crash! BUG: kernel NULL pointer dereference, address: 0000000000000028 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 6 PID: 877 Comm: bash Not tainted 6.5.0-rc4-test-00008-g2c6b6b1029d4-dirty #186 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:tracing_release_file_tr+0xc/0x50 What happens here is that the kprobe event creates a trace_event_file "file" descriptor that represents the file in tracefs to the event. It maintains state of the event (is it enabled for the given instance?). Opening the "enable" file gets a reference to the event "file" descriptor via the open file descriptor. When the kprobe event is deleted, the file is also deleted from the tracefs system which also frees the event "file" descriptor. But as the tracefs file is still opened by user space, it will not be totally removed until the final dput() is called on it. But this is not true with the event "file" descriptor that is already freed. If the user does a write to or simply closes the file descriptor it will reference the event "file" descriptor that was just freed, causing a use-after-free bug. To solve this, add a ref count to the event "file" descriptor as well as a new flag called "FREED". The "file" will not be freed until the last reference is released. But the FREE flag will be set when the event is removed to prevent any more modifications to that event from happening, even if there's still a reference to the event "file" descriptor.

In the Linux kernel, the following vulnerability has been resolved: acpi: Fix suspend with Xen PV Commit f1e525009493 ("x86/boot: Skip realmode init code when running as Xen PV guest") missed one code path accessing real_mode_header, leading to dereferencing NULL when suspending the system under Xen: [ 348.284004] PM: suspend entry (deep) [ 348.289532] Filesystems sync: 0.005 seconds [ 348.291545] Freezing user space processes ... (elapsed 0.000 seconds) done. [ 348.292457] OOM killer disabled. [ 348.292462] Freezing remaining freezable tasks ... (elapsed 0.104 seconds) done. [ 348.396612] printk: Suspending console(s) (use no_console_suspend to debug) [ 348.749228] PM: suspend devices took 0.352 seconds [ 348.769713] ACPI: EC: interrupt blocked [ 348.816077] BUG: kernel NULL pointer dereference, address: 000000000000001c [ 348.816080] #PF: supervisor read access in kernel mode [ 348.816081] #PF: error_code(0x0000) - not-present page [ 348.816083] PGD 0 P4D 0 [ 348.816086] Oops: 0000 [#1] PREEMPT SMP NOPTI [ 348.816089] CPU: 0 PID: 6764 Comm: systemd-sleep Not tainted 6.1.3-1.fc32.qubes.x86_64 #1 [ 348.816092] Hardware name: Star Labs StarBook/StarBook, BIOS 8.01 07/03/2022 [ 348.816093] RIP: e030:acpi_get_wakeup_address+0xc/0x20 Fix that by adding an optional acpi callback allowing to skip setting the wakeup address, as in the Xen PV case this will be handled by the hypervisor anyway.

In the Linux kernel, the following vulnerability has been resolved: usb: xhci: Check endpoint is valid before dereferencing it When the host controller is not responding, all URBs queued to all endpoints need to be killed. This can cause a kernel panic if we dereference an invalid endpoint. Fix this by using xhci_get_virt_ep() helper to find the endpoint and checking if the endpoint is valid before dereferencing it. [233311.853271] xhci-hcd xhci-hcd.1.auto: xHCI host controller not responding, assume dead [233311.853393] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000e8 [233311.853964] pc : xhci_hc_died+0x10c/0x270 [233311.853971] lr : xhci_hc_died+0x1ac/0x270 [233311.854077] Call trace: [233311.854085] xhci_hc_died+0x10c/0x270 [233311.854093] xhci_stop_endpoint_command_watchdog+0x100/0x1a4 [233311.854105] call_timer_fn+0x50/0x2d4 [233311.854112] expire_timers+0xac/0x2e4 [233311.854118] run_timer_softirq+0x300/0xabc [233311.854127] __do_softirq+0x148/0x528 [233311.854135] irq_exit+0x194/0x1a8 [233311.854143] __handle_domain_irq+0x164/0x1d0 [233311.854149] gic_handle_irq.22273+0x10c/0x188 [233311.854156] el1_irq+0xfc/0x1a8 [233311.854175] lpm_cpuidle_enter+0x25c/0x418 [msm_pm] [233311.854185] cpuidle_enter_state+0x1f0/0x764 [233311.854194] do_idle+0x594/0x6ac [233311.854201] cpu_startup_entry+0x7c/0x80 [233311.854209] secondary_start_kernel+0x170/0x198

In the Linux kernel, the following vulnerability has been resolved: nfc: nci: fix possible NULL pointer dereference in send_acknowledge() Handle memory allocation failure from nci_skb_alloc() (calling alloc_skb()) to avoid possible NULL pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: pstore/platform: Add check for kstrdup Add check for the return value of kstrdup() and return the error if it fails in order to avoid NULL pointer dereference.