Date: Tue, 18 Nov 2025 14:23:05 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 291080] nfsrv_updatelock() can use uninitialized memory -> crash Message-ID: <bug-291080-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=291080 Bug ID: 291080 Summary: nfsrv_updatelock() can use uninitialized memory -> crash Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Some People Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: rtm@lcs.mit.edu Attachment #265491 text/plain mime type: Created attachment 265491 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=265491&action=edit fake client that can cause a crash in nfsrv_updatelock() I've attached a demo fake nfs4 client that sends an OPEN rpc to the server asking for a write delegation, and then a LOCK rpc with the stateid from the write delegation (rather than for the open). As a result nfsrv_updatelock() tries to use lop = LIST_FIRST(&stp->ls_lock); ...; if (lop->lo_lfp == lfp) { but the ls_lock list hasn't been initialized for nfsstate stp. # uname -a FreeBSD xxx 16.0-CURRENT FreeBSD 16.0-CURRENT #31 main-n275523-f77ac3afe3e3: Sun Oct 12 16:13:10 AST 2025 root@xxx:/usr/obj/usr/src/amd64.amd64/sys/ # cat /etc/exports V4: / 127.0.0.1 /mnt 127.0.0.1 # cc nfsd535a.c # chmod ogu+rwx /mnt # ./a.out ... Fatal trap 9: general protection fault while in kernel mode rdi: deadc0dedeadc0de rsi: fffffe00d708ad28 rdx: fffffe00d708ac10 panic() at panic+0x43/frame 0xfffffe00d708aa80 trap_fatal() at trap_fatal+0x68/frame 0xfffffe00d708aaa0 calltrap() at calltrap+0x8/frame 0xfffffe00d708aaa0 --- trap 0x9, rip = 0xffffffff80a78ad4, rsp = 0xfffffe00d708ab70, rbp = 0xfffffe00d708abc0 --- nfsrv_updatelock() at nfsrv_updatelock+0x74/frame 0xfffffe00d708abc0 nfsrv_lockctrl() at nfsrv_lockctrl+0x125f/frame 0xfffffe00d708ace0 nfsrvd_lock() at nfsrvd_lock+0x656/frame 0xfffffe00d708b1c0 nfsrvd_dorpc() at nfsrvd_dorpc+0x1672/frame 0xfffffe00d708b3d0 nfssvc_program() at nfssvc_program+0x808/frame 0xfffffe00d708b5d0 svc_run_internal() at svc_run_internal+0xaa8/frame 0xfffffe00d708b700 svc_run() at svc_run+0x280/frame 0xfffffe00d708b760 nfsrvd_nfsd() at nfsrvd_nfsd+0x3d3/frame 0xfffffe00d708b8c0 nfssvc_nfsd() at nfssvc_nfsd+0x535/frame 0xfffffe00d708bde0 sys_nfssvc() at sys_nfssvc+0xcc/frame 0xfffffe00d708be00 amd64_syscall() at amd64_syscall+0x169/frame 0xfffffe00d708bf30 fast_syscall_common() at fast_syscall_common+0xf8/frame 0xfffffe00d708bf30 #0 nfsrv_updatelock (stp=0xffffffd001071500, new_lopp=0xffffffc082ada998, other_lopp=0xffffffc082ada880, lfp=0xffffffd001b92e80) at /usr/rtm/symbsd/src/sys/fs/nfsserver/nfs_nfsdstate.c:3907 #1 0xffffffc00039c4ac in nfsrv_lockctrl (vp=<optimized out>, new_stpp=0xffffffc082ada9a0, new_lopp=0xffffffc082ada998, cfp=0xffffffc082ada9a8, clientid=..., stateidp=0xffffffc082ada988, exp=<optimized out>, nd=<optimized out>, p=0xffffffc082874140) at /usr/rtm/symbsd/src/sys/fs/nfsserver/nfs_nfsdstate.c:2480 #2 0xffffffc0003af518 in nfsrvd_lock (nd=0xffffffc082adb0c0, isdgram=<optimized out>, vp=0xffffffd012346370, exp=0xffffffc082adaf78) at /usr/rtm/symbsd/src/sys/fs/nfsserver/nfs_nfsdserv.c:2630 (gdb) print lop $2 = (struct nfslock *) 0xdeadc0dedeadc0de (gdb) print/x stp->ls_flags $3 = 0x100003 -- You are receiving this mail because: You are the assignee for the bug.help
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