Vulnerabilities

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> virtio_pci: fix vq info pointer lookup via wrong index<br /> <br /> Unbinding a virtio balloon device:<br /> <br /> echo virtio0 &gt; /sys/bus/virtio/drivers/virtio_balloon/unbind<br /> <br /> triggers a NULL pointer dereference. The dmesg says:<br /> <br /> BUG: kernel NULL pointer dereference, address: 0000000000000008<br /> [...]<br /> RIP: 0010:__list_del_entry_valid_or_report+0x5/0xf0<br /> Call Trace:<br /> <br /> vp_del_vqs+0x121/0x230<br /> remove_common+0x135/0x150<br /> virtballoon_remove+0xee/0x100<br /> virtio_dev_remove+0x3b/0x80<br /> device_release_driver_internal+0x187/0x2c0<br /> unbind_store+0xb9/0xe0<br /> kernfs_fop_write_iter.llvm.11660790530567441834+0xf6/0x180<br /> vfs_write+0x2a9/0x3b0<br /> ksys_write+0x5c/0xd0<br /> do_syscall_64+0x54/0x230<br /> entry_SYSCALL_64_after_hwframe+0x29/0x31<br /> [...]<br /> <br /> <br /> The virtio_balloon device registers 5 queues (inflate, deflate, stats,<br /> free_page, reporting) but only the first two are unconditional. The<br /> stats, free_page and reporting queues are each conditional on their<br /> respective feature bits. When any of these features are absent, the<br /> corresponding vqs_info entry has name == NULL, creating holes in the<br /> array.<br /> <br /> The root cause is an indexing mismatch introduced when vq info storage<br /> was changed to be passed as an argument. vp_find_vqs_msix() and<br /> vp_find_vqs_intx() store the info pointer at vp_dev-&gt;vqs[i], where &amp;#39;i&amp;#39;<br /> is the caller&amp;#39;s sparse array index. However, the virtqueue itself gets<br /> vq-&gt;index assigned from queue_idx, a dense index that skips NULL<br /> entries. When holes exist, &amp;#39;i&amp;#39; and queue_idx diverge. Later,<br /> vp_del_vqs() looks up info via vp_dev-&gt;vqs[vq-&gt;index] using the dense<br /> index into the sparsely-populated array, and hits NULL.<br /> <br /> Fix this by storing info at vp_dev-&gt;vqs[queue_idx] instead of<br /> vp_dev-&gt;vqs[i], so the store index matches the lookup index<br /> (vq-&gt;index). Apply the fix to both the MSIX and INTX paths.

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> mm/damon/ops-common: handle extreme intervals in damon_hot_score()<br /> <br /> Fix three issues in damon_hot_score() that comes from wrong handling of<br /> extreme (zero or too high) monitoring intervals user setup.<br /> <br /> When the user sets sampling interval zero, damon_max_nr_accesses(), which<br /> is called from damon_hot_score(), causes a divide-by-zero. Needless to<br /> say, it is a problem.<br /> <br /> When the user sets the aggregation interval zero, the function returns<br /> zero. It is wrong, since the real maximum nr_acceses in the setup should<br /> be one. Worse yet, it can cause another divide-by-zero from its caller,<br /> damon_hot_score(), since it uses damon_max_nr_accesses() return value as a<br /> denominator.<br /> <br /> When the user sets the aggregation interval very high, damon_hot_score()<br /> could return a value out of [0, DAMOS_MAX_SCORE] range. Since the return<br /> value is used as an index to the regions_score_histogram array, which is<br /> DAMOS_MAX_SCORE+1 size, it causes out of bounds array access.<br /> <br /> The issues can be relatively easily reproduced like below. The sysfs<br /> write permission is required, though.<br /> <br /> # ./damo start --damos_action lru_prio --damos_quota_space 100M \<br /> --damos_quota_interval 1s<br /> # cd /sys/kernel/mm/damon/admin/kdamonds/0<br /> # echo 0 &gt; contexts/0/monitoring_attrs/intervals/sample_us<br /> # echo 0 &gt; contexts/0/monitoring_attrs/intervals/aggr_us<br /> # echo commit &gt; state<br /> # dmesg<br /> [...]<br /> [ 131.329762] Oops: divide error: 0000 [#1] SMP NOPTI<br /> [...]<br /> [ 131.336089] RIP: 0010:damon_hot_score+0x27/0xd0<br /> [...]<br /> <br /> Fix the divide-by-zero intervals problems by explicitly handling the zero<br /> intervals in damon_max_nr_accesses(). Fix the out-of-bound array access<br /> by applying [0, DAMOS_MAX_SCORE] bounds before returning from<br /> damon_hot_score().<br /> <br /> The issue was discovered [1] by Sashiko.

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> 6lowpan: fix NHC entry use-after-free on error path<br /> <br /> lowpan_nhc_do_uncompression() looks up an NHC descriptor while holding<br /> lowpan_nhc_lock. If the descriptor has no uncompress callback, the error<br /> path drops the lock before printing nhc-&gt;name.<br /> <br /> lowpan_nhc_del() removes descriptors under the same lock and then relies<br /> on synchronize_net() before the owning module can be unloaded. That only<br /> waits for net RX RCU readers. lowpan_header_decompress() is also exported<br /> and can be reached from callers that are not necessarily covered by the net<br /> core RX critical section, for example the Bluetooth 6LoWPAN L2CAP receive<br /> path.<br /> <br /> This leaves a race where one task drops lowpan_nhc_lock in the error path,<br /> another task unregisters and frees the matching descriptor after<br /> synchronize_net() returns, and the first task then dereferences nhc-&gt;name<br /> for the warning.<br /> <br /> With the post-unlock window widened, KASAN reports:<br /> <br /> BUG: KASAN: slab-use-after-free in lowpan_nhc_do_uncompression+0x1f4/0x220<br /> Read of size 8<br /> lowpan_nhc_do_uncompression<br /> lowpan_header_decompress<br /> <br /> Fix this by printing the warning before dropping lowpan_nhc_lock, so the<br /> descriptor name is read while unregister is still excluded. The malformed<br /> packet is still rejected with -ENOTSUPP.

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> hwrng: virtio: clamp device-reported used.len at copy_data()<br /> <br /> random_recv_done() stores the device-reported used.len directly into<br /> vi-&gt;data_avail. copy_data() then indexes vi-&gt;data[] using<br /> vi-&gt;data_idx (advanced by previous copy_data() calls) and issues a<br /> memcpy() without re-validating either value against the posted<br /> buffer size sizeof(vi-&gt;data) (SMP_CACHE_BYTES bytes, typically 32<br /> or 64).<br /> <br /> A malicious or buggy virtio-rng backend can set used.len beyond<br /> sizeof(vi-&gt;data), steering the memcpy() past the end of the inline<br /> array into adjacent kmalloc-1k slab bytes. hwrng_fillfn() mixes<br /> those bytes into the guest RNG, and guest root can also observe<br /> them directly via /dev/hwrng.<br /> <br /> Concrete impact is inside the guest:<br /> <br /> - Memory-safety / hardening: any virtio-rng backend that<br /> over-reports used.len causes the driver to read past vi-&gt;data<br /> into unrelated slab contents. hwrng_fillfn() is a kernel thread<br /> that runs as soon as the device is probed; no guest userspace<br /> interaction is required to first-trigger the OOB.<br /> <br /> - Cross-boundary leak (confidential-compute threat model): a<br /> malicious hypervisor cooperating with a malicious or compromised<br /> guest root userspace can use /dev/hwrng as a leak channel for<br /> guest-kernel heap data. The host sets a large used.len, guest<br /> root reads /dev/hwrng, and the returned bytes contain guest<br /> kernel slab contents that were adjacent to vi-&gt;data. In<br /> practice, confidential-compute guests (SEV-SNP, TDX) usually<br /> disable virtio-rng entirely, so this path is narrow, but the<br /> fix is still worth carrying because the underlying<br /> memory-safety bug contaminates the guest RNG on any host.<br /> <br /> KASAN confirms the OOB on a 7.1-rc4 guest whose virtio-rng backend<br /> has been patched to report used.len = 0x10000:<br /> <br /> BUG: KASAN: slab-out-of-bounds in virtio_read+0x394/0x5d0<br /> Read of size 64 at addr ffff88800ae0ba20 by task hwrng/52<br /> Call Trace:<br /> __asan_memcpy+0x23/0x60<br /> virtio_read+0x394/0x5d0<br /> hwrng_fillfn+0xb2/0x470<br /> kthread+0x2cc/0x3a0<br /> Allocated by task 1:<br /> probe_common+0xa5/0x660<br /> virtio_dev_probe+0x549/0xbc0<br /> The buggy address belongs to the object at ffff88800ae0b800<br /> which belongs to the cache kmalloc-1k of size 1024<br /> The buggy address is located 0 bytes to the right of<br /> allocated 544-byte region [ffff88800ae0b800, ffff88800ae0ba20)<br /> <br /> Same class of bug as commit c04db81cd028 ("net/9p: Fix buffer<br /> overflow in USB transport layer"), which hardened<br /> usb9pfs_rx_complete() against unchecked device-reported length in<br /> the USB 9p transport.<br /> <br /> With the clamp at point of use and array_index_nospec() in place,<br /> the same harness boots cleanly: copy_data() returns zero for the<br /> bogus report, the device-supplied bytes after data_idx are<br /> discarded, and the driver issues a fresh request.

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> staging: rtl8723bs: fix heap buffer overflow in rtw_cfg80211_set_wpa_ie()<br /> <br /> supplicant_ie is a 256-byte array in struct security_priv. The WPA and<br /> WPA2 IE copy paths use:<br /> <br /> memcpy(padapter-&gt;securitypriv.supplicant_ie, &amp;pwpa[0], wpa_ielen + 2);<br /> <br /> where wpa_ielen is the raw IE length field (u8, 0-255). When a local user<br /> supplies a connect request via nl80211 with a crafted WPA IE of length 255,<br /> wpa_ielen + 2 equals 257, overflowing the 256-byte buffer by one byte into<br /> the adjacent last_mic_err_time field.<br /> <br /> rtw_parse_wpa_ie() does not prevent this: its length consistency check<br /> compares *(wpa_ie+1) against (u8)(wpa_ie_len-2), which is (u8)(255) == 255<br /> when wpa_ie_len = 257, so the check passes silently.<br /> <br /> Add explicit bounds checks for both the WPA and WPA2 paths before the<br /> memcpy, rejecting any IE whose total size (wpa_ielen + 2) exceeds the<br /> supplicant_ie buffer.

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> staging: rtl8723bs: fix OOB read in OnAssocRsp() IE loop<br /> <br /> The IE parsing loop in OnAssocRsp() advances by (pIE-&gt;length + 2) each<br /> iteration but only guards on i length<br /> from pframe[pkt_len], which is one byte past the allocated receive buffer.<br /> <br /> Additionally, even when the header bytes are in bounds, pIE-&gt;length<br /> itself can extend the data window beyond pkt_len, silently passing a<br /> truncated IE to the handler functions.<br /> <br /> Add two guards at the top of the loop body:<br /> 1. Break if fewer than sizeof(*pIE) bytes remain (can&amp;#39;t read header).<br /> 2. Break if the IE&amp;#39;s declared data extends past pkt_len.

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> staging: rtl8723bs: fix WEP length underflow and OOB read in OnAuth()<br /> <br /> OnAuth() has two bugs in the shared-key authentication path.<br /> <br /> When the Privacy bit is set, rtw_wep_decrypt() is called without<br /> verifying that the frame is long enough to contain a valid WEP IV and<br /> ICV. Inside rtw_wep_decrypt(), length is computed as:<br /> <br /> length = len - WLAN_HDR_A3_LEN - iv_len<br /> <br /> and then passed as (length - 4) to crc32_le(). If len is less than<br /> WLAN_HDR_A3_LEN + iv_len + icv_len (32 bytes), length - 4 is negative<br /> and, after the implicit cast to size_t, causes crc32_le() to read far<br /> beyond the frame buffer. Add a minimum length check before accessing<br /> the IV field and calling the decryption path.<br /> <br /> When processing a seq=3 response, rtw_get_ie() stores the Challenge<br /> Text IE length in ie_len, but the subsequent memcmp() always reads 128<br /> bytes regardless of ie_len. IEEE 802.11 mandates a challenge text of<br /> exactly 128 bytes; reject any IE whose length field differs, matching<br /> the check already applied to OnAuthClient().

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> staging: media: ipu7: fix double-free and use-after-free in error paths<br /> <br /> In both ipu7_isys_init() and ipu7_psys_init(), pdata is allocated and<br /> then passed to ipu7_bus_initialize_device(), which stores it in<br /> adev-&gt;pdata. The ipu7_bus_release() function frees adev-&gt;pdata when the<br /> device&amp;#39;s reference count drops to zero.<br /> <br /> Two error paths incorrectly call kfree(pdata) after the device teardown<br /> has already freed it:<br /> <br /> 1. When ipu7_mmu_init() fails: put_device() is called, which drops the<br /> reference count to zero and triggers ipu7_bus_release() -&gt;<br /> kfree(pdata). The subsequent kfree(pdata) is a double-free.<br /> <br /> 2. When ipu7_bus_add_device() fails: it calls auxiliary_device_uninit()<br /> internally, which calls put_device() -&gt; ipu7_bus_release() -&gt;<br /> kfree(pdata). The subsequent kfree(pdata) is again a double-free.<br /> <br /> Note that the kfree(pdata) when ipu7_bus_initialize_device() itself<br /> fails is correct, because in that case auxiliary_device_init() failed<br /> and the release function was never set up, so pdata must be freed<br /> manually.<br /> <br /> Additionally, the error code was not saved before calling put_device(),<br /> causing ERR_CAST() to dereference the already-freed adev pointer when<br /> constructing the return value. Fix this by saving the error from<br /> dev_err_probe() before put_device() and returning ERR_PTR() instead.<br /> <br /> Remove the redundant kfree(pdata) calls and fix the use-after-free in<br /> the return values of the two affected error paths.

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> smb: client: restrict implied bcc[0] exemption to responses without data area<br /> <br /> smb2_check_message() has a long-standing quirk that accepts a response<br /> whose calculated length is one byte larger than the bytes actually<br /> received ("server can return one byte more due to implied bcc[0]").<br /> This was introduced to accommodate servers that omit the trailing bcc[0]<br /> overlap byte when no data area is present.<br /> <br /> However, the exemption is applied unconditionally, regardless of whether<br /> the command actually carries a data area (has_smb2_data_area[]). When a<br /> response with a data area is subject to the +1 exemption, the reported<br /> data can extend one byte beyond the bytes actually received, yet<br /> smb2_check_message() still accepts it. The subsequent decoder then reads<br /> past the end of the receive buffer. This is reachable during NEGOTIATE<br /> and SESSION_SETUP, before the session is established.<br /> <br /> The resulting out-of-bounds reads are visible under KASAN when mounting<br /> against a non-conforming server; both the SPNEGO/negTokenInit and the<br /> NTLMSSP challenge decoders are affected:<br /> <br /> BUG: KASAN: slab-out-of-bounds in asn1_ber_decoder+0x16a7/0x1b00<br /> Read of size 1 at addr ffff8880084d67c0 by task mount.cifs/81<br /> CPU: 1 UID: 0 PID: 81 Comm: mount.cifs Not tainted 7.1.0-rc6 #1<br /> Call Trace:<br /> <br /> dump_stack_lvl+0x4e/0x70<br /> print_report+0x157/0x4c9<br /> kasan_report+0xce/0x100<br /> asn1_ber_decoder+0x16a7/0x1b00<br /> decode_negTokenInit+0x19/0x30<br /> SMB2_negotiate+0x31d9/0x4c90<br /> cifs_negotiate_protocol+0x1f2/0x3f0<br /> cifs_get_smb_ses+0x93f/0x17e0<br /> cifs_mount_get_session+0x7f/0x3a0<br /> cifs_mount+0xb4/0xcf0<br /> cifs_smb3_do_mount+0x23a/0x1500<br /> smb3_get_tree+0x3b0/0x630<br /> vfs_get_tree+0x82/0x2d0<br /> fc_mount+0x10/0x1b0<br /> path_mount+0x50d/0x1de0<br /> __x64_sys_mount+0x20b/0x270<br /> do_syscall_64+0xee/0x590<br /> entry_SYSCALL_64_after_hwframe+0x77/0x7f<br /> <br /> Allocated by task 85:<br /> kmem_cache_alloc_noprof+0x106/0x380<br /> mempool_alloc_noprof+0x116/0x1e0<br /> cifs_small_buf_get+0x31/0x80<br /> allocate_buffers+0x10d/0x2b0<br /> cifs_demultiplex_thread+0x1d5/0x1d50<br /> kthread+0x2c6/0x390<br /> ret_from_fork+0x36e/0x5a0<br /> ret_from_fork_asm+0x1a/0x30<br /> The buggy address is located 0 bytes to the right of<br /> allocated 448-byte region [ffff8880084d6600, ffff8880084d67c0)<br /> which belongs to the cache cifs_small_rq of size 448<br /> <br /> BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x36/0x50<br /> Read of size 329 at addr ffff88800726c678 by task mount.cifs/89<br /> CPU: 0 UID: 0 PID: 89 Comm: mount.cifs Tainted: G B 7.1.0-rc6 #1<br /> Call Trace:<br /> <br /> dump_stack_lvl+0x4e/0x70<br /> print_report+0x157/0x4c9<br /> kasan_report+0xce/0x100<br /> kasan_check_range+0x10f/0x1e0<br /> __asan_memcpy+0x23/0x60<br /> kmemdup_noprof+0x36/0x50<br /> decode_ntlmssp_challenge+0x457/0x680<br /> SMB2_sess_auth_rawntlmssp_negotiate+0x6f0/0xcb0<br /> SMB2_sess_setup+0x219/0x4f0<br /> cifs_setup_session+0x248/0xaf0<br /> cifs_get_smb_ses+0xf79/0x17e0<br /> cifs_mount_get_session+0x7f/0x3a0<br /> cifs_mount+0xb4/0xcf0<br /> cifs_smb3_do_mount+0x23a/0x1500<br /> smb3_get_tree+0x3b0/0x630<br /> vfs_get_tree+0x82/0x2d0<br /> fc_mount+0x10/0x1b0<br /> path_mount+0x50d/0x1de0<br /> __x64_sys_mount+0x20b/0x270<br /> do_syscall_64+0xee/0x590<br /> entry_SYSCALL_64_after_hwframe+0x77/0x7f<br /> <br /> Allocated by task 93:<br /> kmem_cache_alloc_noprof+0x106/0x380<br /> mempool_alloc_noprof+0x116/0x1e0<br /> cifs_small_buf_get+0x31/0x80<br /> allocate_buffers+0x10d/0x2b0<br /> cifs_demultiplex_thread+0x1d5/0x1d50<br /> kthread+0x2c6/0x390<br /> ret_from_fork+0x36e/0x5a0<br /> ret_from_fork_asm+0x1a/0x30<br /> The buggy address is located 120 bytes inside of<br /> allocated 448-byte region [ffff88800726c600, ffff88800726c7c0)<br /> which belongs to the cache cifs_small_rq of size 448<br /> <br /> Restrict the +1 exemption to responses that have no data area, so that<br /> it still covers the bcc[0] omission it was meant for. When a data area<br /> is present, the +1 discrepancy instead means the reported data length<br /> overruns the<br /> ---truncated---

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> staging: vme_user: bound slave read/write to the kern_buf size<br /> <br /> The SLAVE-path helpers buffer_to_user() and buffer_from_user() copy<br /> &amp;#39;count&amp;#39; bytes into/out of the fixed-size kern_buf (size_buf ==<br /> PCI_BUF_SIZE == 0x20000, 128 KiB) using *ppos as the offset, without<br /> bounding *ppos + count against size_buf.<br /> <br /> vme_user_write()/vme_user_read() only clamp count to the VME window size<br /> (image_size = vme_get_size(resource)), which VME_SET_SLAVE sets from the<br /> user-supplied slave.size -- validated against the VME address space (up<br /> to VME_A32_MAX = 4 GiB), not against PCI_BUF_SIZE. When the window<br /> exceeds 128 KiB, a write()/read() copies past the kern_buf allocation.<br /> <br /> Clamp count against size_buf in both helpers, with an early return when<br /> *ppos is already at/after the buffer end. *ppos is &gt;= 0 here (the caller<br /> rejects negative offsets), so size_buf - *ppos cannot wrap. This mirrors<br /> the existing clamp in the MASTER-path helpers resource_to_user() /<br /> resource_from_user(), and matches the read()/write() convention of a<br /> short transfer at end-of-buffer.<br /> <br /> Found by static analysis (CodeQL taint tracking + CBMC bounded model<br /> checking) and confirmed dynamically under KASAN with the vme_fake bridge:<br /> <br /> BUG: KASAN: slab-out-of-bounds in _copy_from_user+0x2d/0x80<br /> Write of size 262144 at addr ffff888004100000 by task trigger/68<br /> _copy_from_user+0x2d/0x80<br /> vme_user_write+0x13e/0x240 [vme_user]<br /> vfs_write+0x1b8/0x7a0<br /> ksys_write+0xb8/0x150

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> tipc: fix out-of-bounds read in broadcast Gap ACK blocks<br /> <br /> A broadcast PROTOCOL/STATE_MSG can carry a Gap ACK blocks record in its<br /> data area. tipc_get_gap_ack_blks() only verifies that the record&amp;#39;s len<br /> field is self-consistent with its ugack_cnt/bgack_cnt counts<br /> (sz == struct_size(p, gacks, ugack_cnt + bgack_cnt)); it does not check<br /> that the record actually fits in the message data area, msg_data_sz().<br /> <br /> The unicast caller tipc_link_proto_rcv() bounds it ("if (glen &gt; dlen)<br /> break;"), but the broadcast caller tipc_bcast_sync_rcv() discards the<br /> returned size, so tipc_link_advance_transmq() copies the record off the<br /> receive skb with an attacker-controlled count:<br /> <br /> this_ga = kmemdup(ga, struct_size(ga, gacks, ga-&gt;bgack_cnt),<br /> GFP_ATOMIC);<br /> <br /> A TIPC neighbour that negotiated TIPC_GAP_ACK_BLOCK triggers it with one<br /> ordinary broadcast STATE_MSG (msg_bc_ack_invalid() clear), sized so its<br /> data area is short, carrying a Gap ACK record with len = 0x400,<br /> bgack_cnt = 0xff and ugack_cnt = 0. len then equals<br /> struct_size(p, gacks, 255), so the consistency check passes and ga is<br /> non-NULL; kmemdup() reads struct_size(ga, gacks, 255) = 1024 bytes out<br /> of the much smaller skb:<br /> <br /> BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x48/0x60<br /> Read of size 1024 at addr ffff0000c7030d38 by task poc864/69<br /> Call trace:<br /> kmemdup_noprof+0x48/0x60<br /> tipc_link_advance_transmq+0x86c/0xb80<br /> tipc_link_bc_ack_rcv+0x19c/0x1e0<br /> tipc_bcast_sync_rcv+0x1c4/0x2c4<br /> tipc_rcv+0x85c/0x1340<br /> tipc_l2_rcv_msg+0xac/0x104<br /> The buggy address belongs to the object at ffff0000c7030d00<br /> which belongs to the cache skbuff_small_head of size 704<br /> The buggy address is located 56 bytes inside of<br /> allocated 704-byte region [ffff0000c7030d00, ffff0000c7030fc0)<br /> <br /> The copied-out bytes are subsequently consumed as gap/ack values, but<br /> the read is already out of bounds at the kmemdup() regardless of how<br /> they are used.<br /> <br /> The unicast STATE path drops such a message: "if (glen &gt; dlen) break;"<br /> skips the rest of STATE_MSG handling and the skb is freed. Make the<br /> broadcast path drop it too. tipc_bcast_sync_rcv() now bounds the record<br /> against msg_data_sz() and, when it does not fit, reports it back through<br /> tipc_node_bc_sync_rcv() to tipc_rcv() so the skb is discarded rather than<br /> processed. ga is not cleared on this path: ga == NULL already means<br /> "legacy peer without Selective ACK", a distinct legitimate state.

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> net: af_key: initialize alg_key_len for IPComp states<br /> <br /> pfkey_msg2xfrm_state() handles the IPComp (SADB_X_SATYPE_IPCOMP) case by<br /> allocating x-&gt;calg and copying only the algorithm name:<br /> <br /> x-&gt;calg = kmalloc_obj(*x-&gt;calg);<br /> if (!x-&gt;calg) {<br /> err = -ENOMEM;<br /> goto out;<br /> }<br /> strcpy(x-&gt;calg-&gt;alg_name, a-&gt;name);<br /> x-&gt;props.calgo = sa-&gt;sadb_sa_encrypt;<br /> <br /> Unlike the authentication (x-&gt;aalg) and encryption (x-&gt;ealg) branches of<br /> the same function, the compression branch never initializes<br /> calg-&gt;alg_key_len. IPComp carries no key and the allocation only<br /> reserves sizeof(struct xfrm_algo) (i.e. no room for a key), so the field<br /> is left containing uninitialized slab data.<br /> <br /> calg-&gt;alg_key_len is later used as a length by xfrm_algo_clone() when an<br /> IPComp state is cloned during XFRM_MSG_MIGRATE:<br /> <br /> xfrm_state_migrate()<br /> xfrm_state_clone_and_setup()<br /> x-&gt;calg = xfrm_algo_clone(orig-&gt;calg);<br /> kmemdup(orig, xfrm_alg_len(orig));<br /> <br /> where xfrm_alg_len() returns sizeof(*alg) + (alg_key_len + 7) / 8. With<br /> a non-zero garbage alg_key_len, kmemdup() reads past the end of the<br /> 68-byte calg object. Adding an IPComp SA via PF_KEY and then migrating<br /> it triggers (net-next, KASAN, init_on_alloc=0):<br /> <br /> BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x44/0x60<br /> Read of size 4164 at addr ff11000025a74980 by task diag2/9287<br /> CPU: 3 UID: 0 PID: 9287 Comm: diag2 7.1.0-rc6-g903db046d557 #1<br /> Call Trace:<br /> <br /> dump_stack_lvl+0x10e/0x1f0<br /> print_report+0xf7/0x600<br /> kasan_report+0xe4/0x120<br /> kasan_check_range+0x105/0x1b0<br /> __asan_memcpy+0x23/0x60<br /> kmemdup_noprof+0x44/0x60<br /> xfrm_state_migrate+0x70a/0x1da0<br /> xfrm_migrate+0x753/0x18a0<br /> xfrm_do_migrate+0xb47/0xf10<br /> xfrm_user_rcv_msg+0x411/0xb50<br /> netlink_rcv_skb+0x158/0x420<br /> xfrm_netlink_rcv+0x71/0x90<br /> netlink_unicast+0x584/0x850<br /> netlink_sendmsg+0x8b0/0xdc0<br /> ____sys_sendmsg+0x9f7/0xb90<br /> ___sys_sendmsg+0x134/0x1d0<br /> __sys_sendmsg+0x16d/0x220<br /> do_syscall_64+0x116/0x7d0<br /> entry_SYSCALL_64_after_hwframe+0x77/0x7f<br /> <br /> <br /> Allocated by task 9287:<br /> kasan_save_stack+0x33/0x60<br /> kasan_save_track+0x14/0x30<br /> __kasan_kmalloc+0xaa/0xb0<br /> pfkey_add+0x2652/0x2ea0<br /> pfkey_process+0x6d0/0x830<br /> pfkey_sendmsg+0x42c/0x850<br /> __sys_sendto+0x461/0x4b0<br /> __x64_sys_sendto+0xe0/0x1c0<br /> do_syscall_64+0x116/0x7d0<br /> entry_SYSCALL_64_after_hwframe+0x77/0x7f<br /> <br /> The buggy address belongs to the object at ff11000025a74980<br /> which belongs to the cache kmalloc-96 of size 96<br /> The buggy address is located 0 bytes inside of<br /> allocated 68-byte region [ff11000025a74980, ff11000025a749c4)<br /> <br /> Depending on the uninitialized value the same field can instead request<br /> an oversized kmemdup() allocation and make the migration clone fail.<br /> <br /> The XFRM netlink path is not affected: verify_one_alg() rejects an<br /> XFRMA_ALG_COMP attribute shorter than xfrm_alg_len(), so a calg added via<br /> XFRM_MSG_NEWSA is always self-consistent.<br /> <br /> Initialize calg-&gt;alg_key_len to 0, matching the aalg/ealg branches.