net_sched: cls_flow: validate TCA_FLOW_RSHIFT attribute
In the Linux kernel, the following vulnerability has been resolved: net_sched: cls_flow: validate TCA_FLOW_RSHIFT attribute syzbot found that TCA_FLOW_RSHIFT attribute was not validated. Right shitfing a 32bit integer is undefined for large shift values. UBSAN: shift-out-of-bounds in net/sched/cls_flow.c:329:23 shift exponent 9445 is too large for 32-bit type 'u32' (aka 'unsigned int') CPU: 1 UID: 0 PID: 54 Comm: kworker/u8:3 Not tainted 6.13.0-rc3-syzkaller-00180-g4f619d518db9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 ubsan_epilogue lib/ubsan.c:231 [inline] __ubsan_handle_shift_out_of_bounds+0x3c8/0x420 lib/ubsan.c:468 flow_classify+0x24d5/0x25b0 net/sched/cls_flow.c:329 tc_classify include/net/tc_wrapper.h:197 [inline] __tcf_classify net/sched/cls_api.c:1771 [inline] tcf_classify+0x420/0x1160 net/sched/cls_api.c:1867 sfb_classify net/sched/sch_sfb.c:260 [inline] sfb_enqueue+0x3ad/0x18b0 net/sched/sch_sfb.c:318 dev_qdisc_enqueue+0x4b/0x290 net/core/dev.c:3793 __dev_xmit_skb net/core/dev.c:3889 [inline] __dev_queue_xmit+0xf0e/0x3f50 net/core/dev.c:4400 dev_queue_xmit include/linux/netdevice.h:3168 [inline] neigh_hh_output include/net/neighbour.h:523 [inline] neigh_output include/net/neighbour.h:537 [inline] ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:236 iptunnel_xmit+0x55d/0
CVE-2025-21653
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-2025-21653
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": "e5dfb815181fcb186d6080ac3a091eadff2d98fe",
"lessThan": "9858f4afeb2e59506e714176bd3e135539a3eeec",
"versionType": "git"
},
{
"status": "affected",
"version": "e5dfb815181fcb186d6080ac3a091eadff2d98fe",
"lessThan": "43658e4a5f2770ad94e93362885ff51c10cf3179",
"versionType": "git"
},
{
"status": "affected",
"version": "e5dfb815181fcb186d6080ac3a091eadff2d98fe",
"lessThan": "a313d6e6d5f3a631cae5a241c392c28868aa5c5e",
"versionType": "git"
},
{
"status": "affected",
"version": "e5dfb815181fcb186d6080ac3a091eadff2d98fe",
"lessThan": "2011749ca96460386844dfc7e0fde53ebee96f3c",
"versionType": "git"
},
{
"status": "affected",
"version": "e5dfb815181fcb186d6080ac3a091eadff2d98fe",
"lessThan": "e54beb9aed2a90dddf4c5d68fcfc9a01f3e40a61",
"versionType": "git"
},
{
"status": "affected",
"version": "e5dfb815181fcb186d6080ac3a091eadff2d98fe",
"lessThan": "6fde663f7321418996645ee602a473457640542f",
"versionType": "git"
},
{
"status": "affected",
"version": "e5dfb815181fcb186d6080ac3a091eadff2d98fe",
"lessThan": "a039e54397c6a75b713b9ce7894a62e06956aa92",
"versionType": "git"
}
],
"programFiles": [
"net/sched/cls_flow.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.25"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.25",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.4.290",
"versionType": "semver",
"lessThanOrEqual": "5.4.*"
},
{
"status": "unaffected",
"version": "5.10.234",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.177",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.125",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.72",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.10",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.13",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/sched/cls_flow.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2025-21653
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #26901 · Revision 1
- Added to Heist Feed
- Publisher date