CVE-2026-98380
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: net/sched: reject IDR error pointers when deleting actions tcf_action_delete() drops the reference held by its lookup before calling tcf_idr_delete_index() with the saved action index. An unlocked classifier can remove that action and reserve the same IDR slot with ERR_PTR(-EBUSY) in between. tcf_idr_delete_index() only checks the lookup result for NULL. It therefore treats the reservation as a tc_action and dereferences tcfa_bindcnt. A hardware execution breakpoint was used to schedule the interleaving without changing the kernel source. KASAN reported this decoded trace: BUG: KASAN: null-ptr-deref in tca_action_gd+0x5b9/0x1010 Read of size 4 at addr 0000000000000010 by task poc/150 Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002 RIP: tca_action_gd+0x5c0/0x1010: arch_atomic_read at arch/x86/include/asm/atomic.h:23 raw_atomic_read at include/linux/atomic/atomic-arch-fallback.h:457 atomic_read at include/linux/atomic/atomic-instrumented.h:33 tcf_idr_delete_index at net/sched/act_api.c:766 tcf_action_delete at net/sched/act_api.c:1859 tcf_del_notify at net/sched/act_api.c:2014 tca_action_gd at net/sched/act_api.c:2064 R13: 0000000000000010 R15: fffffffffffffff0 Kernel panic - not syncing: Fatal exception R15 contains ERR_PTR(-EBUSY), and adding the tcfa_bindcnt offset produces the address in R13. With the guard applied, the same reproducer returned -ENOENT without a KASAN report or panic. Treat error pointers as absent and return -ENOENT.
View original CVE JSON
{
"id": "CVE-2026-98380",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-10-09T08:16:56.400",
"lastModified": "2026-10-19T10:18:41.317",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: reject IDR error pointers when deleting actions\n\ntcf_action_delete() drops the reference held by its lookup before calling\ntcf_idr_delete_index() with the saved action index. An unlocked\nclassifier can remove that action and reserve the same IDR slot with\nERR_PTR(-EBUSY) in between.\n\ntcf_idr_delete_index() only checks the lookup result for NULL. It\ntherefore treats the reservation as a tc_action and dereferences\ntcfa_bindcnt. A hardware execution breakpoint was used to schedule the\ninterleaving without changing the kernel source. KASAN reported this\ndecoded trace:\n\n BUG: KASAN: null-ptr-deref in tca_action_gd+0x5b9/0x1010\n Read of size 4 at addr 0000000000000010 by task poc/150\n Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002\n RIP: tca_action_gd+0x5c0/0x1010:\n arch_atomic_read at arch/x86/include/asm/atomic.h:23\n raw_atomic_read at include/linux/atomic/atomic-arch-fallback.h:457\n atomic_read at include/linux/atomic/atomic-instrumented.h:33\n tcf_idr_delete_index at net/sched/act_api.c:766\n tcf_action_delete at net/sched/act_api.c:1859\n tcf_del_notify at net/sched/act_api.c:2014\n tca_action_gd at net/sched/act_api.c:2064\n R13: 0000000000000010 R15: fffffffffffffff0\n Kernel panic - not syncing: Fatal exception\n\nR15 contains ERR_PTR(-EBUSY), and adding the tcfa_bindcnt offset produces\nthe address in R13. With the guard applied, the same reproducer returned\n-ENOENT without a KASAN report or panic. Treat error pointers as absent\nand return -ENOENT."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/sched/act_api.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
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"versionType": "git",
"status": "affected"
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"status": "affected"
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},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"net/sched/act_api.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "4.19",
"status": "affected"
},
{
"version": "0",
"lessThan": "4.19",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.271",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.222",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.189",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.158",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.112",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.55",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.9",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {},
"references": [
{
"url": "https://git.kernel.org/stable/c/259caa711b7688365676442e2fdb286b8aceaa80",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/39b751a210bf61a374afa82749afc7a77a08bf1d",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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{
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{
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{
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{
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}