CVE-2025-39984 (GCVE-0-2025-39984)
Vulnerability from cvelistv5
Published
2025-10-15 07:56
Modified
2025-10-15 07:56
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
net: tun: Update napi->skb after XDP process
The syzbot report a UAF issue:
BUG: KASAN: slab-use-after-free in skb_reset_mac_header include/linux/skbuff.h:3150 [inline]
BUG: KASAN: slab-use-after-free in napi_frags_skb net/core/gro.c:723 [inline]
BUG: KASAN: slab-use-after-free in napi_gro_frags+0x6e/0x1030 net/core/gro.c:758
Read of size 8 at addr ffff88802ef22c18 by task syz.0.17/6079
CPU: 0 UID: 0 PID: 6079 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xca/0x240 mm/kasan/report.c:482
kasan_report+0x118/0x150 mm/kasan/report.c:595
skb_reset_mac_header include/linux/skbuff.h:3150 [inline]
napi_frags_skb net/core/gro.c:723 [inline]
napi_gro_frags+0x6e/0x1030 net/core/gro.c:758
tun_get_user+0x28cb/0x3e20 drivers/net/tun.c:1920
tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1996
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5c9/0xb30 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
Allocated by task 6079:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:330 [inline]
__kasan_mempool_unpoison_object+0xa0/0x170 mm/kasan/common.c:558
kasan_mempool_unpoison_object include/linux/kasan.h:388 [inline]
napi_skb_cache_get+0x37b/0x6d0 net/core/skbuff.c:295
__alloc_skb+0x11e/0x2d0 net/core/skbuff.c:657
napi_alloc_skb+0x84/0x7d0 net/core/skbuff.c:811
napi_get_frags+0x69/0x140 net/core/gro.c:673
tun_napi_alloc_frags drivers/net/tun.c:1404 [inline]
tun_get_user+0x77c/0x3e20 drivers/net/tun.c:1784
tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1996
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5c9/0xb30 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 6079:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:243 [inline]
__kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2422 [inline]
slab_free mm/slub.c:4695 [inline]
kmem_cache_free+0x18f/0x400 mm/slub.c:4797
skb_pp_cow_data+0xdd8/0x13e0 net/core/skbuff.c:969
netif_skb_check_for_xdp net/core/dev.c:5390 [inline]
netif_receive_generic_xdp net/core/dev.c:5431 [inline]
do_xdp_generic+0x699/0x11a0 net/core/dev.c:5499
tun_get_user+0x2523/0x3e20 drivers/net/tun.c:1872
tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1996
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5c9/0xb30 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
After commit e6d5dbdd20aa ("xdp: add multi-buff support for xdp running in
generic mode"), the original skb may be freed in skb_pp_cow_data() when
XDP program was attached, which was allocated in tun_napi_alloc_frags().
However, the napi->skb still point to the original skb, update it after
XDP process.
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/net/tun.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "953200d56fc23eebf80a5ad9eed6e2e8a3065093",
"status": "affected",
"version": "e6d5dbdd20aa6a86974af51deb9414cd2e7794cb",
"versionType": "git"
},
{
"lessThan": "1697577e1669b0321d02cd848384a5d33e284296",
"status": "affected",
"version": "e6d5dbdd20aa6a86974af51deb9414cd2e7794cb",
"versionType": "git"
},
{
"lessThan": "1091860a16a86ccdd77c09f2b21a5f634f5ab9ec",
"status": "affected",
"version": "e6d5dbdd20aa6a86974af51deb9414cd2e7794cb",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/net/tun.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.9"
},
{
"lessThan": "6.9",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.50",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.16.*",
"status": "unaffected",
"version": "6.16.10",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.17",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.50",
"versionStartIncluding": "6.9",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.16.10",
"versionStartIncluding": "6.9",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.17",
"versionStartIncluding": "6.9",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: tun: Update napi-\u003eskb 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 \u003cTASK\u003e\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 \u003c/TASK\u003e\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-\u003eskb still point to the original skb, update it after\nXDP process."
}
],
"providerMetadata": {
"dateUpdated": "2025-10-15T07:56:03.438Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"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-\u003eskb after XDP process",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2025-39984",
"datePublished": "2025-10-15T07:56:03.438Z",
"dateReserved": "2025-04-16T07:20:57.150Z",
"dateUpdated": "2025-10-15T07:56:03.438Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1",
"vulnerability-lookup:meta": {
"nvd": "{\"cve\":{\"id\":\"CVE-2025-39984\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-10-15T08:15:36.400\",\"lastModified\":\"2025-10-16T15:29:11.563\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nnet: tun: Update napi-\u003eskb 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 \u003cTASK\u003e\\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 \u003c/TASK\u003e\\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-\u003eskb still point to the original skb, update it after\\nXDP process.\"}],\"metrics\":{},\"references\":[{\"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\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
}
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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