Linux Kernel bpf link iterator useafterfree (CVE-2026-98378)
CVE-2026-98378 Published on October 9, 2026
bpf: Skip unsettled links in link iterator
In the Linux kernel, the following vulnerability has been resolved:
bpf: Skip unsettled links in link iterator
bpf_link_prime() inserts a link into link_idr before anon_inode_getfile()
succeeds and before bpf_link_settle() publishes the ID in link->id.
bpf_link_by_id() treats such an ID-zero link as unsettled, but the link
iterator takes a reference without this check.
If anon_inode_getfile() then fails, the creator removes the ID and frees
its still-private link directly. The iterator is left with a dangling
reference and its next bpf_link_put() accesses freed memory.
Treat ID-zero entries as transient in bpf_link_get_curr_or_next(), just as
bpf_link_by_id() does.
BUG: KASAN: slab-use-after-free in bpf_link_put
Write of size 8 by task exp/384
Call Trace:
bpf_link_put kernel/bpf/syscall.c:3372
bpf_link_seq_next kernel/bpf/link_iter.c:33
bpf_seq_read kernel/bpf/bpf_iter.c:158
vfs_read fs/read_write.c:572
ksys_read fs/read_write.c:716
do_syscall_64 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe arch/x86/entry/entry_64.S:121
Kernel panic - not syncing: KASAN: panic_on_warn set ...
Products Associated with CVE-2026-98378
Want to know whenever a new CVE is published for Linux Kernel? stack.watch will email you.
Affected Versions
Linux:- Version 9f88361273082825d9f0d13a543d49f9fa0d44a8 and below 68930f8d40ab4c10ca3b019f076136758fd100a8 is affected.
- Version 9f88361273082825d9f0d13a543d49f9fa0d44a8 and below c251ed48bd9063cf7de6049421e78b6de989060f is affected.
- Version 9f88361273082825d9f0d13a543d49f9fa0d44a8 and below 798a61edbc436cacdb659927d067368eeb1e30e2 is affected.
- Version 9f88361273082825d9f0d13a543d49f9fa0d44a8 and below 6e271f093d15d323f42de26f66556af53fa8e19f is affected.
- Version 9f88361273082825d9f0d13a543d49f9fa0d44a8 and below 87ce4b53b7436b50fc984f0a6afaf77f68ac5573 is affected.
- Version 9f88361273082825d9f0d13a543d49f9fa0d44a8 and below 50e80e2bb5e2be8515205b9c496b9640ddefa434 is affected.
- Version 5.19 is affected.
- Before 5.19 is unaffected.
- Version 6.1.189, <= 6.1.* is unaffected.
- Version 6.6.158, <= 6.6.* is unaffected.
- Version 6.12.112, <= 6.12.* is unaffected.
- Version 6.18.55, <= 6.18.* is unaffected.
- Version 7.2.9, <= 7.2.* is unaffected.
- Version 7.3-rc5, <= * is unaffected.