diff options
| author | Masami Hiramatsu <mhiramat@kernel.org> | 2020-12-03 13:50:37 +0900 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-12-06 09:58:13 +0100 |
| commit | 4e9a5ae8df5b3365183150f6df49e49dece80d8c (patch) | |
| tree | 3f10655b516680582aceaaae84846f4e53465d26 /tools | |
| parent | 8dcc0e19dfbd73ad6b3172924d6da8f7f3f8b3b0 (diff) | |
x86/uprobes: Do not use prefixes.nbytes when looping over prefixes.bytes
Since insn.prefixes.nbytes can be bigger than the size of
insn.prefixes.bytes[] when a prefix is repeated, the proper check must
be
insn.prefixes.bytes[i] != 0 and i < 4
instead of using insn.prefixes.nbytes.
Introduce a for_each_insn_prefix() macro for this purpose. Debugged by
Kees Cook <keescook@chromium.org>.
[ bp: Massage commit message, sync with the respective header in tools/
and drop "we". ]
Fixes: 2b1444983508 ("uprobes, mm, x86: Add the ability to install and remove uprobes breakpoints")
Reported-by: syzbot+9b64b619f10f19d19a7c@syzkaller.appspotmail.com
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/160697103739.3146288.7437620795200799020.stgit@devnote2
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/arch/x86/include/asm/insn.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/tools/arch/x86/include/asm/insn.h b/tools/arch/x86/include/asm/insn.h index 568854b14d0a..52c6262e6bfd 100644 --- a/tools/arch/x86/include/asm/insn.h +++ b/tools/arch/x86/include/asm/insn.h @@ -201,6 +201,21 @@ static inline int insn_offset_immediate(struct insn *insn) return insn_offset_displacement(insn) + insn->displacement.nbytes; } +/** + * for_each_insn_prefix() -- Iterate prefixes in the instruction + * @insn: Pointer to struct insn. + * @idx: Index storage. + * @prefix: Prefix byte. + * + * Iterate prefix bytes of given @insn. Each prefix byte is stored in @prefix + * and the index is stored in @idx (note that this @idx is just for a cursor, + * do not change it.) + * Since prefixes.nbytes can be bigger than 4 if some prefixes + * are repeated, it cannot be used for looping over the prefixes. + */ +#define for_each_insn_prefix(insn, idx, prefix) \ + for (idx = 0; idx < ARRAY_SIZE(insn->prefixes.bytes) && (prefix = insn->prefixes.bytes[idx]) != 0; idx++) + #define POP_SS_OPCODE 0x1f #define MOV_SREG_OPCODE 0x8e |