net/sched: reject IDR error pointers when deleting actions
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 r
CVE-2026-98380
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-98380
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "0190c1d452a91c38a3462abdd81752be1b9006a8",
"lessThan": "39b751a210bf61a374afa82749afc7a77a08bf1d",
"versionType": "git"
},
{
"status": "affected",
"version": "0190c1d452a91c38a3462abdd81752be1b9006a8",
"lessThan": "dd80a7519824b72c8fcfd3cc50cb93f7e2d90923",
"versionType": "git"
},
{
"status": "affected",
"version": "0190c1d452a91c38a3462abdd81752be1b9006a8",
"lessThan": "6bf076258aac4e0af69ef317656c31ce6444d647",
"versionType": "git"
},
{
"status": "affected",
"version": "0190c1d452a91c38a3462abdd81752be1b9006a8",
"lessThan": "6c9f07bf8800171de2cd3f02815cebe1f4d45f2d",
"versionType": "git"
},
{
"status": "affected",
"version": "0190c1d452a91c38a3462abdd81752be1b9006a8",
"lessThan": "259caa711b7688365676442e2fdb286b8aceaa80",
"versionType": "git"
},
{
"status": "affected",
"version": "0190c1d452a91c38a3462abdd81752be1b9006a8",
"lessThan": "968550a439f64bd1a6c0d88efb92e4f082f84a26",
"versionType": "git"
},
{
"status": "affected",
"version": "0190c1d452a91c38a3462abdd81752be1b9006a8",
"lessThan": "a9551f26287debe6d8aa6e8841974661065b975f",
"versionType": "git"
},
{
"status": "affected",
"version": "0190c1d452a91c38a3462abdd81752be1b9006a8",
"lessThan": "c82b797abe668d0b668601a93ba2c0b071a63574",
"versionType": "git"
}
],
"programFiles": [
"net/sched/act_api.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.19"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.19",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.271",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.222",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.189",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.158",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.112",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.55",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.9",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/sched/act_api.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98380
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #38452 · Revision 1
- Added to Heist Feed
- Publisher date