{"id":2229276,"url":"http://patchwork.ozlabs.org/api/1.1/patches/2229276/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-cifs-client/patch/20260428025110.38825-1-FredTheDude@proton.me/","project":{"id":12,"url":"http://patchwork.ozlabs.org/api/1.1/projects/12/?format=json","name":"Linux CIFS Client","link_name":"linux-cifs-client","list_id":"linux-cifs.vger.kernel.org","list_email":"linux-cifs@vger.kernel.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20260428025110.38825-1-FredTheDude@proton.me>","date":"2026-04-28T02:51:10","name":"[RFC] smb: client: fix NULL pointer dereference in smb2_compound_op","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"2b5af3b3cee265c3c9d0ad3b9ed9f5d4c0cc035a","submitter":{"id":93268,"url":"http://patchwork.ozlabs.org/api/1.1/people/93268/?format=json","name":"Fredric Cover","email":"fredric.cover.lkernel@gmail.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linux-cifs-client/patch/20260428025110.38825-1-FredTheDude@proton.me/mbox/","series":[{"id":501751,"url":"http://patchwork.ozlabs.org/api/1.1/series/501751/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-cifs-client/list/?series=501751","date":"2026-04-28T02:51:10","name":"[RFC] smb: client: fix NULL pointer dereference in smb2_compound_op","version":1,"mbox":"http://patchwork.ozlabs.org/series/501751/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2229276/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2229276/checks/","tags":{},"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-cifs@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256\n header.s=20251104 header.b=tIHGAWKO;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c0a:e001:db::12fc:5321; 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This bypasses the\ninitialization of rqst[0] by SMB2_open_init().\n\nHowever, the 'finished' cleanup block unconditionally attempts to\ncall SMB2_open_free() on rqst[0]. If SMB2_open_init() was skipped,\nrqst[0].rq_iov is NULL, leading to a NULL pointer dereference.\n\nCheck for a valid rq_iov before attempting to free the request\nto prevent the crash in handle-reuse scenarios.\n\nSigned-off-by: Fredric Cover \n---\nI am new to writing code for the Linux kernel.\nPlease be patient with me and feel free to point out any\nobvious mistakes I made. \nI tested this patch in a user-space skeleton clone using ASan.\nI only have access to a shallow clone and cannot find the \noriginal commit for the 'Fixes:' line.\n---\n fs/smb/client/smb2inode.c | 8 +++++++-\n 1 file changed, 7 insertions(+), 1 deletion(-)","diff":"diff --git a/fs/smb/client/smb2inode.c b/fs/smb/client/smb2inode.c\nindex c6dd282fc..aed96eeba 100644\n--- a/fs/smb/client/smb2inode.c\n+++ b/fs/smb/client/smb2inode.c\n@@ -552,7 +552,13 @@ static int smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon,\n \n finished:\n \tnum_rqst = 0;\n-\tSMB2_open_free(&rqst[num_rqst++]);\n+\t/*\n+\t * If cfile was passed, the open was skipped; check rq_iov\n+\t * to ensure we don't try to dereference a NULL pointer.\n+\t */\n+\tif (rqst[num_rqst].rq_iov)\n+\t\tSMB2_open_free(&rqst[num_rqst]);\n+\tnum_rqst++;\n \tif (rc == -EREMCHG) {\n \t\tpr_warn_once(\"server share %s deleted\\n\", tcon->tree_name);\n \t\ttcon->need_reconnect = true;\n","prefixes":["RFC"]}