CVE-2026-98449None▾ Sunlit

smb: client: delete compound mids on send failure before unlock

In the Linux kernel, the following vulnerability has been resolved: smb: client: delete compound mids on send failure before unlock When sending a compound request fails, smb_send_rqst() kicks off a reconnect. compound_send_recv() stil…

▾ Sunlit zone — Low / medium · no exploitation signal

Depth score3/ 100 · Minimal

impact 2.8 · likelihood 0 · exploitation 0

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Proof of concept

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Published

Oct 18, 2026

Updated

Oct 19, 2026

CVSS

—

Vendor

Linux

Product

Linux

CWE

—

Depth score

3 · Minimal

EPSS

0.16% · p5

Platforms

—

Source

CVEORG

Vector

—

EPSS history

Exploit-prediction probability, daily snapshots since Oct 20.

0.2% → 0.2%

Timeline

Disclosure to exploitation, from the record and what we observed since indexing it.

3 events · 2 days

Oct 18, 2026Published
Disclosed via CVEORG
Oct 19, 2026Record revised
Last analysed / modified upstream
Oct 20, 2026EPSS first tracked
0.2%

Linux #cve.org

Affected

Linux >= ee258d79159afed52ca9372aeb9c1a51e89b32ee < 70783946f3b5d0c06ec7df0f5e7bec2bfad24efb
Linux >= ee258d79159afed52ca9372aeb9c1a51e89b32ee < 8f6f8a48399f82f4a83f7b9f25b9707e0062a4f9
Linux 3c57a0be487088b08d9c88998f911eb4a7ba36e4
Linux >= 4.20.11 < 4.21
Linux 5.0

Full technical detail▾

Overview

In the Linux kernel, the following vulnerability has been resolved:

smb: client: delete compound mids on send failure before unlock

When sending a compound request fails, smb_send_rqst() kicks off a reconnect. compound_send_recv() still has those mids on pending_mid_q, but it unlocks the server without removing them first.

During reconnect, cifs_abort_connection() walks pending_mid_q and runs each mid callback. With no response yet, those callbacks return credits and drop in_flight. Then compound_send_recv()'s send-error path returns the same credits again. in_flight ends up decremented twice and smb2_add_credits() WARNs.

syzbot hits this during SMB2_negotiate when the socket send fails.

cifs_call_async() already calls delete_mid() before unlock on send failure. Do the same for compound chains and set cancelled_mid[] so the out: path does not delete them again.

Affected

Linux >= ee258d79159afed52ca9372aeb9c1a51e89b32ee < 70783946f3b5d0c06ec7df0f5e7bec2bfad24efb
Linux >= ee258d79159afed52ca9372aeb9c1a51e89b32ee < 8f6f8a48399f82f4a83f7b9f25b9707e0062a4f9
Linux 3c57a0be487088b08d9c88998f911eb4a7ba36e4
Linux >= 4.20.11 < 4.21
Linux 5.0

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

References

Related vulnerabilities

Connected by shared product, vendor, weakness, or advisory.

#cve.org

smb: client: delete compound mids on send failure before unlock

▾ Sunlit zone — Low / medium · no exploitation signal

Depth score3/ 100 · Minimal

impact 2.8 · likelihood 0 · exploitation 0

Overview

In the Linux kernel, the following vulnerability has been resolved:

smb: client: delete compound mids on send failure before unlock

When sending a compound request fails, smb_send_rqst() kicks off a reconnect. compound_send_recv() still has those mids on pending_mid_q, but it unlocks the server without removing them first.

syzbot hits this during SMB2_negotiate when the socket send fails.

cifs_call_async() already calls delete_mid() before unlock on send failure. Do the same for compound chains and set cancelled_mid[] so the out: path does not delete them again.