In the Linux kernel, the following vulnerability has been resolved: gtp: fix use-after-free and null-ptr-deref in gtp_genl_dump_pdp() The gtp_net_ops pernet operations structure for the subsystem must be registered before registering the generic netlink family. Syzkaller hit 'general protection fault in gtp_genl_dump_pdp' bug: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 1 PID: 5826 Comm: gtp Not tainted 6.8.0-rc3-std-def-alt1 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-alt1 04/01/2014 RIP: 0010:gtp_genl_dump_pdp+0x1be/0x800 [gtp] Code: c6 89 c6 e8 64 e9 86 df 58 45 85 f6 0f 85 4e 04 00 00 e8 c5 ee 86 df 48 8b 54 24 18 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 de 05 00 00 48 8b 44 24 18 4c 8b 30 4c 39 f0 74 RSP: 0018:ffff888014107220 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 000000…

In the Linux kernel, the following vulnerability has been resolved: ext4: fix double-free of blocks due to wrong extents moved_len In ext4_move_extents(), moved_len is only updated when all moves are successfully executed, and only discards orig_inode and donor_inode preallocations when moved_len is not zero. When the loop fails to exit after successfully moving some extents, moved_len is not updated and remains at 0, so it does not discard the preallocations. If the moved extents overlap with the preallocated extents, the overlapped extents are freed twice in ext4_mb_release_inode_pa() and ext4_process_freed_data() (as described in commit 94d7c16cbbbd ("ext4: Fix double-free of blocks with EXT4_IOC_MOVE_EXT")), and bb_free is incremented twice. Hence when trim is executed, a zero-division bug is triggered in mb_update_avg_fragment_size() because bb_free is not zero and bb_fragments is zero. Therefore, update move_len after each extent move to avoid the issue.

In the Linux kernel, the following vulnerability has been resolved: crypto: ccp - Fix null pointer dereference in __sev_platform_shutdown_locked The SEV platform device can be shutdown with a null psp_master, e.g., using DEBUG_TEST_DRIVER_REMOVE. Found using KASAN: [ 137.148210] ccp 0000:23:00.1: enabling device (0000 -> 0002) [ 137.162647] ccp 0000:23:00.1: no command queues available [ 137.170598] ccp 0000:23:00.1: sev enabled [ 137.174645] ccp 0000:23:00.1: psp enabled [ 137.178890] general protection fault, probably for non-canonical address 0xdffffc000000001e: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN NOPTI [ 137.182693] KASAN: null-ptr-deref in range [0x00000000000000f0-0x00000000000000f7] [ 137.182693] CPU: 93 PID: 1 Comm: swapper/0 Not tainted 6.8.0-rc1+ #311 [ 137.182693] RIP: 0010:__sev_platform_shutdown_locked+0x51/0x180 [ 137.182693] Code: 08 80 3c 08 00 0f 85 0e 01 00 00 48 8b 1d 67 b6 01 08 48 b8 00 00 00 00 00 fc ff df 48 8d bb f0 00 00 00 48 89 f9 48 c1 …

In the Linux kernel, the following vulnerability has been resolved: ceph: prevent use-after-free in encode_cap_msg() In fs/ceph/caps.c, in encode_cap_msg(), "use after free" error was caught by KASAN at this line - 'ceph_buffer_get(arg->xattr_buf);'. This implies before the refcount could be increment here, it was freed. In same file, in "handle_cap_grant()" refcount is decremented by this line - 'ceph_buffer_put(ci->i_xattrs.blob);'. It appears that a race occurred and resource was freed by the latter line before the former line could increment it. encode_cap_msg() is called by __send_cap() and __send_cap() is called by ceph_check_caps() after calling __prep_cap(). __prep_cap() is where arg->xattr_buf is assigned to ci->i_xattrs.blob. This is the spot where the refcount must be increased to prevent "use after free" error.

In the Linux kernel, the following vulnerability has been resolved: fs,hugetlb: fix NULL pointer dereference in hugetlbs_fill_super When configuring a hugetlb filesystem via the fsconfig() syscall, there is a possible NULL dereference in hugetlbfs_fill_super() caused by assigning NULL to ctx->hstate in hugetlbfs_parse_param() when the requested pagesize is non valid. E.g: Taking the following steps: fd = fsopen("hugetlbfs", FSOPEN_CLOEXEC); fsconfig(fd, FSCONFIG_SET_STRING, "pagesize", "1024", 0); fsconfig(fd, FSCONFIG_CMD_CREATE, NULL, NULL, 0); Given that the requested "pagesize" is invalid, ctxt->hstate will be replaced with NULL, losing its previous value, and we will print an error: ... ... case Opt_pagesize: ps = memparse(param->string, &rest); ctx->hstate = h; if (!ctx->hstate) { pr_err("Unsupported page size %lu MB\n", ps / SZ_1M); return -EINVAL; } return 0; ... ... This is a problem because later on, we will dereference ctxt-…

In the Linux kernel, the following vulnerability has been resolved: can: j1939: Fix UAF in j1939_sk_match_filter during setsockopt(SO_J1939_FILTER) Lock jsk->sk to prevent UAF when setsockopt(..., SO_J1939_FILTER, ...) modifies jsk->filters while receiving packets. Following trace was seen on affected system: ================================================================== BUG: KASAN: slab-use-after-free in j1939_sk_recv_match_one+0x1af/0x2d0 [can_j1939] Read of size 4 at addr ffff888012144014 by task j1939/350 CPU: 0 PID: 350 Comm: j1939 Tainted: G W OE 6.5.0-rc5 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: print_report+0xd3/0x620 ? kasan_complete_mode_report_info+0x7d/0x200 ? j1939_sk_recv_match_one+0x1af/0x2d0 [can_j1939] kasan_report+0xc2/0x100 ? j1939_sk_recv_match_one+0x1af/0x2d0 [can_j1939] __asan_load4+0x84/0xb0 j1939_sk_recv_match_one+0x1af/0x2d0 [can_j1939] j1939_sk_recv+0x20b…

In the Linux kernel, the following vulnerability has been resolved: tipc: Check the bearer type before calling tipc_udp_nl_bearer_add() syzbot reported the following general protection fault [1]: general protection fault, probably for non-canonical address 0xdffffc0000000010: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000080-0x0000000000000087] ... RIP: 0010:tipc_udp_is_known_peer+0x9c/0x250 net/tipc/udp_media.c:291 ... Call Trace: <TASK> tipc_udp_nl_bearer_add+0x212/0x2f0 net/tipc/udp_media.c:646 tipc_nl_bearer_add+0x21e/0x360 net/tipc/bearer.c:1089 genl_family_rcv_msg_doit+0x1fc/0x2e0 net/netlink/genetlink.c:972 genl_family_rcv_msg net/netlink/genetlink.c:1052 [inline] genl_rcv_msg+0x561/0x800 net/netlink/genetlink.c:1067 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2544 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1076 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x53b/0x810 net/netlink/af_netlink.c:13…

In the Linux kernel, the following vulnerability has been resolved: ALSA: sh: aica: reorder cleanup operations to avoid UAF bugs The dreamcastcard->timer could schedule the spu_dma_work and the spu_dma_work could also arm the dreamcastcard->timer. When the snd_pcm_substream is closing, the aica_channel will be deallocated. But it could still be dereferenced in the worker thread. The reason is that del_timer() will return directly regardless of whether the timer handler is running or not and the worker could be rescheduled in the timer handler. As a result, the UAF bug will happen. The racy situation is shown below: (Thread 1) | (Thread 2) snd_aicapcm_pcm_close() | ... | run_spu_dma() //worker | mod_timer() flush_work() | del_timer() | aica_period_elapsed() //timer kfree(dreamcastcard->channel) | schedule_work() …

In the Linux kernel, the following vulnerability has been resolved: mm/sparsemem: fix race in accessing memory_section->usage The below race is observed on a PFN which falls into the device memory region with the system memory configuration where PFN's are such that [ZONE_NORMAL ZONE_DEVICE ZONE_NORMAL]. Since normal zone start and end pfn contains the device memory PFN's as well, the compaction triggered will try on the device memory PFN's too though they end up in NOP(because pfn_to_online_page() returns NULL for ZONE_DEVICE memory sections). When from other core, the section mappings are being removed for the ZONE_DEVICE region, that the PFN in question belongs to, on which compaction is currently being operated is resulting into the kernel crash with CONFIG_SPASEMEM_VMEMAP enabled. The crash logs can be seen at [1]. compact_zone() memunmap_pages ------------- --------------- __pageblock_pfn_to_page ...... (a)pfn_valid(): valid_section()//return true (b)…

In the Linux kernel, the following vulnerability has been resolved: llc: call sock_orphan() at release time syzbot reported an interesting trace [1] caused by a stale sk->sk_wq pointer in a closed llc socket. In commit ff7b11aa481f ("net: socket: set sock->sk to NULL after calling proto_ops::release()") Eric Biggers hinted that some protocols are missing a sock_orphan(), we need to perform a full audit. In net-next, I plan to clear sock->sk from sock_orphan() and amend Eric patch to add a warning. [1] BUG: KASAN: slab-use-after-free in list_empty include/linux/list.h:373 [inline] BUG: KASAN: slab-use-after-free in waitqueue_active include/linux/wait.h:127 [inline] BUG: KASAN: slab-use-after-free in sock_def_write_space_wfree net/core/sock.c:3384 [inline] BUG: KASAN: slab-use-after-free in sock_wfree+0x9a8/0x9d0 net/core/sock.c:2468 Read of size 8 at addr ffff88802f4fc880 by task ksoftirqd/1/27 CPU: 1 PID: 27 Comm: ksoftirqd/1 Not tainted 6.8.0-rc1-syzkaller-00049-g6098d87eaf…