CVE-2026-45842
- Source
- https://cve.org/CVERecord?id=CVE-2026-45842
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-45842.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-45842
- Downstream
AZL (1)
BELL (1)
DEBIAN (1)
ECHO (1)
openSUSE (2)
ROOT (5)
SUSE (11)
UBUNTU (1)
- Related
- Published
- 2026-05-27T09:24:42Z
- Modified
- 2026-10-08T02:51:24Z
- Summary
- slip: reject VJ receive packets on instances with no rstate array
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
slip: reject VJ receive packets on instances with no rstate array
slhc_init() accepts rslots == 0 as a valid configuration, with the documented meaning of 'no receive compression'. In that case the allocation loop in slhc_init() is skipped, so comp->rstate stays NULL and comp->rslot_limit stays 0 (from the kzalloc of struct slcompress).
The receive helpers do not defend against that configuration. slhc_uncompress() dereferences comp->rstate[x] when the VJ header carries an explicit connection ID, and slhc_remember() later assigns cs = &comp->rstate[...] after only comparing the packet's slot number to comp->rslot_limit. Because rslot_limit is 0, slot 0 passes the range check, and the code dereferences a NULL rstate.
The configuration is reachable in-tree through PPP. PPPIOCSMAXCID stores its argument in a signed int, and (val >> 16) uses arithmetic shift. Passing 0xffff0000 therefore sign-extends to -1, so val2 + 1 is 0 and ppp_generic.c ends up calling slhc_init(0, 1). Because /dev/ppp open is gated by ns_capable(CAP_NET_ADMIN), the whole path is reachable from an unprivileged user namespace. Once the malformed VJ state is installed, any inbound VJ-compressed or VJ-uncompressed frame that selects slot 0 crashes the kernel in softirq context:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:slhc_uncompress (drivers/net/slip/slhc.c:519) Call Trace: ppp_receive_nonmp_frame (drivers/net/ppp/ppp_generic.c:2466) ppp_input (drivers/net/ppp/ppp_generic.c:2359) ppp_async_process (drivers/net/ppp/ppp_async.c:492) tasklet_action_common (kernel/softirq.c:926) handle_softirqs (kernel/softirq.c:623) run_ksoftirqd (kernel/softirq.c:1055) smpboot_thread_fn (kernel/smpboot.c:160) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:164)
Reject the receive side on such instances instead of touching rstate. slhc_uncompress() falls through to its existing 'bad' label, which bumps sls_i_error and enters the toss state. slhc_remember() mirrors that with an explicit sls_i_error increment followed by slhc_toss(); the sls_i_runt counter is not used here because a missing rstate is an internal configuration state, not a runt packet.
The transmit path is unaffected: the only in-tree caller that picks rslots from userspace (ppp_generic.c) still supplies tslots >= 1, and slip.c always calls slhc_init(16, 16), so comp->tstate remains valid and slhc_compress() continues to work.
- Database specific
{ "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45842.json" }- References
-
- https://git.kernel.org/stable/c/3d71c961febddd855d3ae9a519eeb96c8023f430
- https://git.kernel.org/stable/c/4aa9eca6fda2919027dfd7a7cc69334982d89586
- https://git.kernel.org/stable/c/72304fec672e8aac9ee7b9c475db96b37cca8d8d
- https://git.kernel.org/stable/c/7b0d9e878ec2b21d99ae8051b3dda59cdb66c152
- https://git.kernel.org/stable/c/9e1ff0eead073c4f46d874ad2526b7dda5465faf
- https://git.kernel.org/stable/c/c6980e8b1a86288167f34966fa5219031999b6f1
- https://git.kernel.org/stable/c/de42f86e2cf5028a97e74c25869d1a962b13c301
- https://git.kernel.org/stable/c/e76607442d5b73e1ba6768f501ef815bb58c2c0e
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45842.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-45842
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced4ab42d78e37a294ac7bc56901d563c642e03c4aeFixed3d71c961febddd855d3ae9a519eeb96c8023f430Fixed72304fec672e8aac9ee7b9c475db96b37cca8d8dFixed4aa9eca6fda2919027dfd7a7cc69334982d89586Fixedc6980e8b1a86288167f34966fa5219031999b6f1Fixedde42f86e2cf5028a97e74c25869d1a962b13c301Fixed9e1ff0eead073c4f46d874ad2526b7dda5465fafFixed7b0d9e878ec2b21d99ae8051b3dda59cdb66c152Fixede76607442d5b73e1ba6768f501ef815bb58c2c0e
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced2.6.32.70Fixed2.6.33
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced3.2.75Fixed3.3
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced3.4.111Fixed3.5
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced3.10.96Fixed3.11
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced3.12.53Fixed3.13
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced3.14.60Fixed3.15
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced3.18.27Fixed3.19
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced4.1.17Fixed4.2
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced4.3.5Fixed4.4
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced42fc512469e78939c1e419d3310c47de55bdcbb8
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduceddf085f1cb3acd3d75408ff94f366983873bce7d2
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduceda1c3860d3c5fc62bd35f089bcb03f18a37242de9
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedf82699de104eaf8a7ffc2849a566a94818dd8a3c
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced354b254af5c1350de9586af75fe5a821b35bfb33
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced5148857f5d4c812cc918cf4627f7880521e987eb
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced82185755d90c8047c6f4b589c39998ff3d4ca3ad
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduceda50a93cc99286dc444c7e5ccc7dfb9d58c2d346d
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced6b4fa561e26526c62636414d267342c945084f44
Affected versions
v2.*
v3.*
v4.*
Linux / Kernel
Package
- Name
- Kernel
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced4.4.0Fixed5.10.258
- Type
- ECOSYSTEM
- Events
-
Introduced5.11.0Fixed5.15.209
- Type
- ECOSYSTEM
- Events
-
Introduced5.16.0Fixed6.1.175
- Type
- ECOSYSTEM
- Events
-
Introduced6.2.0Fixed6.6.141
- Type
- ECOSYSTEM
- Events
-
Introduced6.7.0Fixed6.12.91
- Type
- ECOSYSTEM
- Events
-
Introduced6.13.0Fixed6.18.33
- Type
- ECOSYSTEM
- Events
-
Introduced6.19.0Fixed7.0.10