Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_cake: Fix incorrect qlen reduction in cake_drop In cake_drop(), qdisc_tree_reduce_backlog() is used to update the qlen and backlog of the qdisc hierarchy. Its caller, cake_enqueue(), assumes that the parent qdisc will enqueue the current packet. However, this assumption breaks when cake_enqueue() returns NET_XMIT_CN: the parent qdisc stops enqueuing current packet, leaving the tree qlen/backlog accounting inconsistent. This mismatch can lead to a NULL dereference (e.g., when the parent Qdisc is qfq_qdisc). This patch computes the qlen/backlog delta in a more robust way by observing the difference before and after the series of cake_drop() calls, and then compensates the qdisc tree accounting if cake_enqueue() returns NET_XMIT_CN. To ensure correct compensation when ACK thinning is enabled, a new variable is introduced to keep qlen unchanged.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected de04ddd2980b48caa8d7e24a7db2742917a8b280 before a3f4e3de41a3f115db35276c6b186ccbc913934a; affected 0dacfc5372e314d1219f03e64dde3ab495a5a25e before 38abf6e931b169ea88d7529b49096f53a5dcf8fe; affected 710866fc0a64eafcb8bacd91bcb1329eb7e5035f before fcb91be52eb6e92e00b533ebd7c77fecada537e1; affected aa12ee1c1bd260943fd6ab556d8635811c332eeb before d01f0e072dadb02fe10f436b940dd957aff0d7d4; affected ff57186b2cc39766672c4c0332323933e5faaa88 before 0b6216f9b3d1c33c76f74511026e5de5385ee520; affected 15de71d06a400f7fdc15bf377a2552b0ec437cf5 before 529c284cc2815c8350860e9a31722050fe7117cb; affected 15de71d06a400f7fdc15bf377a2552b0ec437cf5 before 3ed6c458530a547ed0c9ea0b02b19bab620be88b; affected 15de71d06a400f7fdc15bf377a2552b0ec437cf5 before 9fefc78f7f02d71810776fdeb119a05a946a27cc; affected 7689ab22de36f8db19095f6bdf11f28cfde92f5c; affected 62d591dde4defb1333d202410609c4ddeae060b3; affected 5.10.241 before 5.10.248; affected 5.15.190 before 5.15.198; affected 6.1.149 before 6.1.160; affected 6.6.103 before 6.6.120; affected 6.12.44 before 6.12.63; affected 5.4.297 before 5.5; affected 6.16.4 before 6.17 |
| Linux / Linux | affected 6.17; unaffected 0 before 6.17; unaffected 5.10.248 through 5.10.*; unaffected 5.15.198 through 5.15.*; unaffected 6.1.160 through 6.1.*; unaffected 6.6.120 through 6.6.*; unaffected 6.12.63 through 6.12.*; unaffected 6.17.13 through 6.17.*; unaffected 6.18.2 through 6.18.*; unaffected 6.19 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/a3f4e3de41a3f115db35276c6b186ccbc913934a
- https://git.kernel.org/stable/c/38abf6e931b169ea88d7529b49096f53a5dcf8fe
- https://git.kernel.org/stable/c/fcb91be52eb6e92e00b533ebd7c77fecada537e1
- https://git.kernel.org/stable/c/d01f0e072dadb02fe10f436b940dd957aff0d7d4
- https://git.kernel.org/stable/c/0b6216f9b3d1c33c76f74511026e5de5385ee520
- https://git.kernel.org/stable/c/529c284cc2815c8350860e9a31722050fe7117cb
- https://git.kernel.org/stable/c/3ed6c458530a547ed0c9ea0b02b19bab620be88b
- https://git.kernel.org/stable/c/9fefc78f7f02d71810776fdeb119a05a946a27cc