{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2025-39984", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.150Z", "datePublished": "2025-10-15T07:56:03.438Z", "dateUpdated": "2025-10-15T07:56:03.438Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2025-10-15T07:56:03.438Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: tun: Update napi->skb after XDP process\n\nThe syzbot report a UAF issue:\n\n BUG: KASAN: slab-use-after-free in skb_reset_mac_header include/linux/skbuff.h:3150 [inline]\n BUG: KASAN: slab-use-after-free in napi_frags_skb net/core/gro.c:723 [inline]\n BUG: KASAN: slab-use-after-free in napi_gro_frags+0x6e/0x1030 net/core/gro.c:758\n Read of size 8 at addr ffff88802ef22c18 by task syz.0.17/6079\n CPU: 0 UID: 0 PID: 6079 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)\n Call Trace:\n <TASK>\n dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [inline]\n print_report+0xca/0x240 mm/kasan/report.c:482\n kasan_report+0x118/0x150 mm/kasan/report.c:595\n skb_reset_mac_header include/linux/skbuff.h:3150 [inline]\n napi_frags_skb net/core/gro.c:723 [inline]\n napi_gro_frags+0x6e/0x1030 net/core/gro.c:758\n tun_get_user+0x28cb/0x3e20 drivers/net/tun.c:1920\n tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1996\n new_sync_write fs/read_write.c:593 [inline]\n vfs_write+0x5c9/0xb30 fs/read_write.c:686\n ksys_write+0x145/0x250 fs/read_write.c:738\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n </TASK>\n\n Allocated by task 6079:\n kasan_save_stack mm/kasan/common.c:47 [inline]\n kasan_save_track+0x3e/0x80 mm/kasan/common.c:68\n unpoison_slab_object mm/kasan/common.c:330 [inline]\n __kasan_mempool_unpoison_object+0xa0/0x170 mm/kasan/common.c:558\n kasan_mempool_unpoison_object include/linux/kasan.h:388 [inline]\n napi_skb_cache_get+0x37b/0x6d0 net/core/skbuff.c:295\n __alloc_skb+0x11e/0x2d0 net/core/skbuff.c:657\n napi_alloc_skb+0x84/0x7d0 net/core/skbuff.c:811\n napi_get_frags+0x69/0x140 net/core/gro.c:673\n tun_napi_alloc_frags drivers/net/tun.c:1404 [inline]\n tun_get_user+0x77c/0x3e20 drivers/net/tun.c:1784\n tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1996\n new_sync_write fs/read_write.c:593 [inline]\n vfs_write+0x5c9/0xb30 fs/read_write.c:686\n ksys_write+0x145/0x250 fs/read_write.c:738\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n Freed by task 6079:\n kasan_save_stack mm/kasan/common.c:47 [inline]\n kasan_save_track+0x3e/0x80 mm/kasan/common.c:68\n kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576\n poison_slab_object mm/kasan/common.c:243 [inline]\n __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275\n kasan_slab_free include/linux/kasan.h:233 [inline]\n slab_free_hook mm/slub.c:2422 [inline]\n slab_free mm/slub.c:4695 [inline]\n kmem_cache_free+0x18f/0x400 mm/slub.c:4797\n skb_pp_cow_data+0xdd8/0x13e0 net/core/skbuff.c:969\n netif_skb_check_for_xdp net/core/dev.c:5390 [inline]\n netif_receive_generic_xdp net/core/dev.c:5431 [inline]\n do_xdp_generic+0x699/0x11a0 net/core/dev.c:5499\n tun_get_user+0x2523/0x3e20 drivers/net/tun.c:1872\n tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1996\n new_sync_write fs/read_write.c:593 [inline]\n vfs_write+0x5c9/0xb30 fs/read_write.c:686\n ksys_write+0x145/0x250 fs/read_write.c:738\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nAfter commit e6d5dbdd20aa (\"xdp: add multi-buff support for xdp running in\ngeneric mode\"), the original skb may be freed in skb_pp_cow_data() when\nXDP program was attached, which was allocated in tun_napi_alloc_frags().\nHowever, the napi->skb still point to the original skb, update it after\nXDP process."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/net/tun.c"], "versions": [{"version": "e6d5dbdd20aa6a86974af51deb9414cd2e7794cb", "lessThan": "953200d56fc23eebf80a5ad9eed6e2e8a3065093", "status": "affected", "versionType": "git"}, {"version": "e6d5dbdd20aa6a86974af51deb9414cd2e7794cb", "lessThan": "1697577e1669b0321d02cd848384a5d33e284296", "status": "affected", "versionType": "git"}, {"version": "e6d5dbdd20aa6a86974af51deb9414cd2e7794cb", "lessThan": "1091860a16a86ccdd77c09f2b21a5f634f5ab9ec", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/net/tun.c"], "versions": [{"version": "6.9", "status": "affected"}, {"version": "0", "lessThan": "6.9", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.50", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.16.10", "lessThanOrEqual": "6.16.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.17", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.12.50"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.16.10"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.17"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/953200d56fc23eebf80a5ad9eed6e2e8a3065093"}, {"url": "https://git.kernel.org/stable/c/1697577e1669b0321d02cd848384a5d33e284296"}, {"url": "https://git.kernel.org/stable/c/1091860a16a86ccdd77c09f2b21a5f634f5ab9ec"}], "title": "net: tun: Update napi->skb after XDP process", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: tun: Update napi->skb after XDP process\n\nThe syzbot report a UAF issue:\n\n BUG: KASAN: slab-use-after-free in skb_reset_mac_header include/linux/skbuff.h:3150 [inline]\n BUG: KASAN: slab-use-after-free in napi_frags_skb net/core/gro.c:723 [inline]\n BUG: KASAN: slab-use-after-free in napi_gro_frags+0x6e/0x1030 net/core/gro.c:758\n Read of size 8 at addr ffff88802ef22c18 by task syz.0.17/6079\n CPU: 0 UID: 0 PID: 6079 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)\n Call Trace:\n <TASK>\n dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [inline]\n print_report+0xca/0x240 mm/kasan/report.c:482\n kasan_report+0x118/0x150 mm/kasan/report.c:595\n skb_reset_mac_header include/linux/skbuff.h:3150 [inline]\n napi_frags_skb net/core/gro.c:723 [inline]\n napi_gro_frags+0x6e/0x1030 net/core/gro.c:758\n tun_get_user+0x28cb/0x3e20 drivers/net/tun.c:1920\n tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1996\n new_sync_write fs/read_write.c:593 [inline]\n vfs_write+0x5c9/0xb30 fs/read_write.c:686\n ksys_write+0x145/0x250 fs/read_write.c:738\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n </TASK>\n\n Allocated by task 6079:\n kasan_save_stack mm/kasan/common.c:47 [inline]\n kasan_save_track+0x3e/0x80 mm/kasan/common.c:68\n unpoison_slab_object mm/kasan/common.c:330 [inline]\n __kasan_mempool_unpoison_object+0xa0/0x170 mm/kasan/common.c:558\n kasan_mempool_unpoison_object include/linux/kasan.h:388 [inline]\n napi_skb_cache_get+0x37b/0x6d0 net/core/skbuff.c:295\n __alloc_skb+0x11e/0x2d0 net/core/skbuff.c:657\n napi_alloc_skb+0x84/0x7d0 net/core/skbuff.c:811\n napi_get_frags+0x69/0x140 net/core/gro.c:673\n tun_napi_alloc_frags drivers/net/tun.c:1404 [inline]\n tun_get_user+0x77c/0x3e20 drivers/net/tun.c:1784\n tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1996\n new_sync_write fs/read_write.c:593 [inline]\n vfs_write+0x5c9/0xb30 fs/read_write.c:686\n ksys_write+0x145/0x250 fs/read_write.c:738\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n Freed by task 6079:\n kasan_save_stack mm/kasan/common.c:47 [inline]\n kasan_save_track+0x3e/0x80 mm/kasan/common.c:68\n kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576\n poison_slab_object mm/kasan/common.c:243 [inline]\n __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275\n kasan_slab_free include/linux/kasan.h:233 [inline]\n slab_free_hook mm/slub.c:2422 [inline]\n slab_free mm/slub.c:4695 [inline]\n kmem_cache_free+0x18f/0x400 mm/slub.c:4797\n skb_pp_cow_data+0xdd8/0x13e0 net/core/skbuff.c:969\n netif_skb_check_for_xdp net/core/dev.c:5390 [inline]\n netif_receive_generic_xdp net/core/dev.c:5431 [inline]\n do_xdp_generic+0x699/0x11a0 net/core/dev.c:5499\n tun_get_user+0x2523/0x3e20 drivers/net/tun.c:1872\n tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1996\n new_sync_write fs/read_write.c:593 [inline]\n vfs_write+0x5c9/0xb30 fs/read_write.c:686\n ksys_write+0x145/0x250 fs/read_write.c:738\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nAfter commit e6d5dbdd20aa (\"xdp: add multi-buff support for xdp running in\ngeneric mode\"), the original skb may be freed in skb_pp_cow_data() when\nXDP program was attached, which was allocated in tun_napi_alloc_frags().\nHowever, the napi->skb still point to the original skb, update it after\nXDP process."}], "id": "CVE-2025-39984", "lastModified": "2025-10-15T08:15:36.400", "metrics": {}, "published": "2025-10-15T08:15:36.400", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1091860a16a86ccdd77c09f2b21a5f634f5ab9ec"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1697577e1669b0321d02cd848384a5d33e284296"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/953200d56fc23eebf80a5ad9eed6e2e8a3065093"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{}