{"id":"CVE-2023-53186","summary":"skbuff: Fix a race between coalescing and releasing SKBs","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nskbuff: Fix a race between coalescing and releasing SKBs\n\nCommit 1effe8ca4e34 (\"skbuff: fix coalescing for page_pool fragment\nrecycling\") allowed coalescing to proceed with non page pool page and page\npool page when @from is cloned, i.e.\n\nto-\u003epp_recycle    --\u003e false\nfrom-\u003epp_recycle  --\u003e true\nskb_cloned(from)  --\u003e true\n\nHowever, it actually requires skb_cloned(@from) to hold true until\ncoalescing finishes in this situation. If the other cloned SKB is\nreleased while the merging is in process, from_shinfo-\u003enr_frags will be\nset to 0 toward the end of the function, causing the increment of frag\npage _refcount to be unexpectedly skipped resulting in inconsistent\nreference counts. Later when SKB(@to) is released, it frees the page\ndirectly even though the page pool page is still in use, leading to\nuse-after-free or double-free errors. So it should be prohibited.\n\nThe double-free error message below prompted us to investigate:\nBUG: Bad page state in process swapper/1  pfn:0e0d1\npage:00000000c6548b28 refcount:-1 mapcount:0 mapping:0000000000000000\nindex:0x2 pfn:0xe0d1\nflags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff)\nraw: 000fffffc0000000 0000000000000000 ffffffff00000101 0000000000000000\nraw: 0000000000000002 0000000000000000 ffffffffffffffff 0000000000000000\npage dumped because: nonzero _refcount\n\nCPU: 1 PID: 0 Comm: swapper/1 Tainted: G            E      6.2.0+\nCall Trace:\n \u003cIRQ\u003e\ndump_stack_lvl+0x32/0x50\nbad_page+0x69/0xf0\nfree_pcp_prepare+0x260/0x2f0\nfree_unref_page+0x20/0x1c0\nskb_release_data+0x10b/0x1a0\nnapi_consume_skb+0x56/0x150\nnet_rx_action+0xf0/0x350\n? __napi_schedule+0x79/0x90\n__do_softirq+0xc8/0x2b1\n__irq_exit_rcu+0xb9/0xf0\ncommon_interrupt+0x82/0xa0\n\u003c/IRQ\u003e\n\u003cTASK\u003e\nasm_common_interrupt+0x22/0x40\nRIP: 0010:default_idle+0xb/0x20","modified":"2026-04-02T09:43:46.437330Z","published":"2025-09-15T14:04:38.954Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53186.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0646dc31ca886693274df5749cd0c8c1eaaeb5ca"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5f692c992a3bb9a8018e3488098b401a4229e7ec"},{"type":"WEB","url":"https://git.kernel.org/stable/c/71850b5af92da21b4862a9bc55bda61091247d00"},{"type":"WEB","url":"https://git.kernel.org/stable/c/906a6689bb0191ad2a44131a3377006aa098af59"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53186.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-53186"},{"type":"PACKAGE","url":"https://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":[{"introduced":"53e0961da1c7bbdabd1abebb20de403ec237ec09"},{"fixed":"906a6689bb0191ad2a44131a3377006aa098af59"},{"fixed":"71850b5af92da21b4862a9bc55bda61091247d00"},{"fixed":"5f692c992a3bb9a8018e3488098b401a4229e7ec"},{"fixed":"0646dc31ca886693274df5749cd0c8c1eaaeb5ca"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-53186.json"}}],"schema_version":"1.7.5"}