From a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 Mon Sep 17 00:00:00 2001 From: Jinke Han Date: Tue, 8 Sep 2026 15:37:42 +0800 Subject: x86/kprobes: Fix crash when probing CS CALL instructions When using eBPF to probe CS CALL instructions within a function, a crash can be triggered. The eBPF tool probes offset 257 of the __hrtimer_run_queues() function: <__hrtimer_run_queues+249>: nopl 0x0(%rax,%rax,1) <__hrtimer_run_queues+254>: mov %r14,%rdi <__hrtimer_run_queues+257>: cs call <__x86_indirect_thunk_r12> <__hrtimer_run_queues+263>: mov %eax,%r12d <__hrtimer_run_queues+266>: xchg %ax,%ax <__hrtimer_run_queues+268>: mov %r13,%rdi Which triggers this crash: BUG: unable to handle page fault for address: 00000000000f41c9 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP NOPTI CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P RIP: 0010:__hrtimer_run_queues+0x106/0x230 Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is at the 6th byte of the above CS CALL instruction. Since the CS CALL instruction occupies 6 bytes, the exception occurred in the middle of that call instruction. The root cause is that when using eBPF tools to probe in the middle of a function, a kprobe with INT3 is used as the underlying implementation. During single-step emulation of the original CALL instruction, int3_emulate_call() assumes that the probed CALL instruction is 5 bytes long. However, the actual CS-prefixed CALL instruction occupies 6 bytes, so it constructs an incorrect exception return address. When the CPU returns from the kprobe handler, the next instruction to be executed is at the address of the last byte of that CS CALL instruction. Coincidentally, starting from that address, the CPU fetches and decodes a completely different instruction, which ultimately triggers a kernel crash. Fix the issue by using the actual instruction length obtained from the instruction decoder when constructing the exception return address, rather than relying on the hardcoded CALL_INSN_SIZE macro. [ mingo: Refined the changelog ] Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step") Suggested-by: Masami Hiramatsu (Google) Signed-off-by: Jinke Han Signed-off-by: Ingo Molnar Reviewed-by: Masami Hiramatsu (Google) Acked-by: Yafang Shao Acked-by: Borislav Petkov Cc: Peter Zijlstra Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000 --- fs/afs/protocol_uae.h | 132 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 132 insertions(+) create mode 100644 fs/afs/protocol_uae.h (limited to 'fs/afs/protocol_uae.h') diff --git a/fs/afs/protocol_uae.h b/fs/afs/protocol_uae.h new file mode 100644 index 000000000..1b3d1060b --- /dev/null +++ b/fs/afs/protocol_uae.h @@ -0,0 +1,132 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Universal AFS Error codes (UAE). + * + * Copyright (C) 2003, Daria Phoebe Brashear + * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved. + */ + +enum { + UAEPERM = 0x2f6df00, /* Operation not permitted */ + UAENOENT = 0x2f6df01, /* No such file or directory */ + UAESRCH = 0x2f6df02, /* No such process */ + UAEINTR = 0x2f6df03, /* Interrupted system call */ + UAEIO = 0x2f6df04, /* I/O error */ + UAENXIO = 0x2f6df05, /* No such device or address */ + UAE2BIG = 0x2f6df06, /* Arg list too long */ + UAENOEXEC = 0x2f6df07, /* Exec format error */ + UAEBADF = 0x2f6df08, /* Bad file number */ + UAECHILD = 0x2f6df09, /* No child processes */ + UAEAGAIN = 0x2f6df0a, /* Try again */ + UAENOMEM = 0x2f6df0b, /* Out of memory */ + UAEACCES = 0x2f6df0c, /* Permission denied */ + UAEFAULT = 0x2f6df0d, /* Bad address */ + UAENOTBLK = 0x2f6df0e, /* Block device required */ + UAEBUSY = 0x2f6df0f, /* Device or resource busy */ + UAEEXIST = 0x2f6df10, /* File exists */ + UAEXDEV = 0x2f6df11, /* Cross-device link */ + UAENODEV = 0x2f6df12, /* No such device */ + UAENOTDIR = 0x2f6df13, /* Not a directory */ + UAEISDIR = 0x2f6df14, /* Is a directory */ + UAEINVAL = 0x2f6df15, /* Invalid argument */ + UAENFILE = 0x2f6df16, /* File table overflow */ + UAEMFILE = 0x2f6df17, /* Too many open files */ + UAENOTTY = 0x2f6df18, /* Not a typewriter */ + UAETXTBSY = 0x2f6df19, /* Text file busy */ + UAEFBIG = 0x2f6df1a, /* File too large */ + UAENOSPC = 0x2f6df1b, /* No space left on device */ + UAESPIPE = 0x2f6df1c, /* Illegal seek */ + UAEROFS = 0x2f6df1d, /* Read-only file system */ + UAEMLINK = 0x2f6df1e, /* Too many links */ + UAEPIPE = 0x2f6df1f, /* Broken pipe */ + UAEDOM = 0x2f6df20, /* Math argument out of domain of func */ + UAERANGE = 0x2f6df21, /* Math result not representable */ + UAEDEADLK = 0x2f6df22, /* Resource deadlock would occur */ + UAENAMETOOLONG = 0x2f6df23, /* File name too long */ + UAENOLCK = 0x2f6df24, /* No record locks available */ + UAENOSYS = 0x2f6df25, /* Function not implemented */ + UAENOTEMPTY = 0x2f6df26, /* Directory not empty */ + UAELOOP = 0x2f6df27, /* Too many symbolic links encountered */ + UAEWOULDBLOCK = 0x2f6df28, /* Operation would block */ + UAENOMSG = 0x2f6df29, /* No message of desired type */ + UAEIDRM = 0x2f6df2a, /* Identifier removed */ + UAECHRNG = 0x2f6df2b, /* Channel number out of range */ + UAEL2NSYNC = 0x2f6df2c, /* Level 2 not synchronized */ + UAEL3HLT = 0x2f6df2d, /* Level 3 halted */ + UAEL3RST = 0x2f6df2e, /* Level 3 reset */ + UAELNRNG = 0x2f6df2f, /* Link number out of range */ + UAEUNATCH = 0x2f6df30, /* Protocol driver not attached */ + UAENOCSI = 0x2f6df31, /* No CSI structure available */ + UAEL2HLT = 0x2f6df32, /* Level 2 halted */ + UAEBADE = 0x2f6df33, /* Invalid exchange */ + UAEBADR = 0x2f6df34, /* Invalid request descriptor */ + UAEXFULL = 0x2f6df35, /* Exchange full */ + UAENOANO = 0x2f6df36, /* No anode */ + UAEBADRQC = 0x2f6df37, /* Invalid request code */ + UAEBADSLT = 0x2f6df38, /* Invalid slot */ + UAEBFONT = 0x2f6df39, /* Bad font file format */ + UAENOSTR = 0x2f6df3a, /* Device not a stream */ + UAENODATA = 0x2f6df3b, /* No data available */ + UAETIME = 0x2f6df3c, /* Timer expired */ + UAENOSR = 0x2f6df3d, /* Out of streams resources */ + UAENONET = 0x2f6df3e, /* Machine is not on the network */ + UAENOPKG = 0x2f6df3f, /* Package not installed */ + UAEREMOTE = 0x2f6df40, /* Object is remote */ + UAENOLINK = 0x2f6df41, /* Link has been severed */ + UAEADV = 0x2f6df42, /* Advertise error */ + UAESRMNT = 0x2f6df43, /* Srmount error */ + UAECOMM = 0x2f6df44, /* Communication error on send */ + UAEPROTO = 0x2f6df45, /* Protocol error */ + UAEMULTIHOP = 0x2f6df46, /* Multihop attempted */ + UAEDOTDOT = 0x2f6df47, /* RFS specific error */ + UAEBADMSG = 0x2f6df48, /* Not a data message */ + UAEOVERFLOW = 0x2f6df49, /* Value too large for defined data type */ + UAENOTUNIQ = 0x2f6df4a, /* Name not unique on network */ + UAEBADFD = 0x2f6df4b, /* File descriptor in bad state */ + UAEREMCHG = 0x2f6df4c, /* Remote address changed */ + UAELIBACC = 0x2f6df4d, /* Can not access a needed shared library */ + UAELIBBAD = 0x2f6df4e, /* Accessing a corrupted shared library */ + UAELIBSCN = 0x2f6df4f, /* .lib section in a.out corrupted */ + UAELIBMAX = 0x2f6df50, /* Attempting to link in too many shared libraries */ + UAELIBEXEC = 0x2f6df51, /* Cannot exec a shared library directly */ + UAEILSEQ = 0x2f6df52, /* Illegal byte sequence */ + UAERESTART = 0x2f6df53, /* Interrupted system call should be restarted */ + UAESTRPIPE = 0x2f6df54, /* Streams pipe error */ + UAEUSERS = 0x2f6df55, /* Too many users */ + UAENOTSOCK = 0x2f6df56, /* Socket operation on non-socket */ + UAEDESTADDRREQ = 0x2f6df57, /* Destination address required */ + UAEMSGSIZE = 0x2f6df58, /* Message too long */ + UAEPROTOTYPE = 0x2f6df59, /* Protocol wrong type for socket */ + UAENOPROTOOPT = 0x2f6df5a, /* Protocol not available */ + UAEPROTONOSUPPORT = 0x2f6df5b, /* Protocol not supported */ + UAESOCKTNOSUPPORT = 0x2f6df5c, /* Socket type not supported */ + UAEOPNOTSUPP = 0x2f6df5d, /* Operation not supported on transport endpoint */ + UAEPFNOSUPPORT = 0x2f6df5e, /* Protocol family not supported */ + UAEAFNOSUPPORT = 0x2f6df5f, /* Address family not supported by protocol */ + UAEADDRINUSE = 0x2f6df60, /* Address already in use */ + UAEADDRNOTAVAIL = 0x2f6df61, /* Cannot assign requested address */ + UAENETDOWN = 0x2f6df62, /* Network is down */ + UAENETUNREACH = 0x2f6df63, /* Network is unreachable */ + UAENETRESET = 0x2f6df64, /* Network dropped connection because of reset */ + UAECONNABORTED = 0x2f6df65, /* Software caused connection abort */ + UAECONNRESET = 0x2f6df66, /* Connection reset by peer */ + UAENOBUFS = 0x2f6df67, /* No buffer space available */ + UAEISCONN = 0x2f6df68, /* Transport endpoint is already connected */ + UAENOTCONN = 0x2f6df69, /* Transport endpoint is not connected */ + UAESHUTDOWN = 0x2f6df6a, /* Cannot send after transport endpoint shutdown */ + UAETOOMANYREFS = 0x2f6df6b, /* Too many references: cannot splice */ + UAETIMEDOUT = 0x2f6df6c, /* Connection timed out */ + UAECONNREFUSED = 0x2f6df6d, /* Connection refused */ + UAEHOSTDOWN = 0x2f6df6e, /* Host is down */ + UAEHOSTUNREACH = 0x2f6df6f, /* No route to host */ + UAEALREADY = 0x2f6df70, /* Operation already in progress */ + UAEINPROGRESS = 0x2f6df71, /* Operation now in progress */ + UAESTALE = 0x2f6df72, /* Stale NFS file handle */ + UAEUCLEAN = 0x2f6df73, /* Structure needs cleaning */ + UAENOTNAM = 0x2f6df74, /* Not a XENIX named type file */ + UAENAVAIL = 0x2f6df75, /* No XENIX semaphores available */ + UAEISNAM = 0x2f6df76, /* Is a named type file */ + UAEREMOTEIO = 0x2f6df77, /* Remote I/O error */ + UAEDQUOT = 0x2f6df78, /* Quota exceeded */ + UAENOMEDIUM = 0x2f6df79, /* No medium found */ + UAEMEDIUMTYPE = 0x2f6df7a, /* Wrong medium type */ +}; -- cgit v1.3.1