mirror of
https://github.com/qemu/qemu.git
synced 2024-12-15 15:33:29 +08:00
e64e27d5cb
`struct dirent' returned from readdir(3) could be shorter (or longer) than `sizeof(struct dirent)', thus memcpy of sizeof length will overread into unallocated page causing SIGSEGV. Example stack trace: #0 0x00005555559ebeed v9fs_co_readdir_many (/usr/bin/qemu-system-x86_64 + 0x497eed) #1 0x00005555559ec2e9 v9fs_readdir (/usr/bin/qemu-system-x86_64 + 0x4982e9) #2 0x0000555555eb7983 coroutine_trampoline (/usr/bin/qemu-system-x86_64 + 0x963983) #3 0x00007ffff73e0be0 n/a (n/a + 0x0) While fixing this, provide a helper for any future `struct dirent' cloning. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/841 Cc: qemu-stable@nongnu.org Co-authored-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Dmitry V. Levin <ldv@altlinux.org> Signed-off-by: Vitaly Chikunov <vt@altlinux.org> Tested-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Acked-by: Greg Kurz <groug@kaod.org> Tested-by: Vitaly Chikunov <vt@altlinux.org> Message-Id: <20220216181821.3481527-1-vt@altlinux.org> [C.S. - Fix typo in source comment. ] Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
76 lines
2.2 KiB
C
76 lines
2.2 KiB
C
/*
|
|
* 9p
|
|
*
|
|
* Copyright IBM, Corp. 2011
|
|
*
|
|
* Authors:
|
|
* Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
|
|
*
|
|
* This work is licensed under the terms of the GNU GPL, version 2. See
|
|
* the COPYING file in the top-level directory.
|
|
*
|
|
*/
|
|
|
|
#ifndef QEMU_9P_SYNTH_H
|
|
#define QEMU_9P_SYNTH_H
|
|
|
|
typedef struct V9fsSynthNode V9fsSynthNode;
|
|
typedef ssize_t (*v9fs_synth_read)(void *buf, int len, off_t offset,
|
|
void *arg);
|
|
typedef ssize_t (*v9fs_synth_write)(void *buf, int len, off_t offset,
|
|
void *arg);
|
|
typedef struct V9fsSynthNodeAttr {
|
|
int mode;
|
|
int inode;
|
|
int nlink;
|
|
v9fs_synth_read read;
|
|
v9fs_synth_write write;
|
|
} V9fsSynthNodeAttr;
|
|
|
|
struct V9fsSynthNode {
|
|
QLIST_HEAD(, V9fsSynthNode) child;
|
|
QLIST_ENTRY(V9fsSynthNode) sibling;
|
|
char name[NAME_MAX];
|
|
V9fsSynthNodeAttr *attr;
|
|
V9fsSynthNodeAttr actual_attr;
|
|
void *private;
|
|
int open_count;
|
|
};
|
|
|
|
typedef struct V9fsSynthOpenState {
|
|
off_t offset;
|
|
V9fsSynthNode *node;
|
|
struct dirent dent;
|
|
/*
|
|
* Ensure there is enough space for 'dent' above, some systems have a
|
|
* d_name size of just 1, which would cause a buffer overrun.
|
|
*/
|
|
char dent_trailing_space[NAME_MAX];
|
|
} V9fsSynthOpenState;
|
|
|
|
int qemu_v9fs_synth_mkdir(V9fsSynthNode *parent, int mode,
|
|
const char *name, V9fsSynthNode **result);
|
|
int qemu_v9fs_synth_add_file(V9fsSynthNode *parent, int mode,
|
|
const char *name, v9fs_synth_read read,
|
|
v9fs_synth_write write, void *arg);
|
|
|
|
/* qtest stuff */
|
|
|
|
#define QTEST_V9FS_SYNTH_WALK_FILE "WALK%d"
|
|
#define QTEST_V9FS_SYNTH_LOPEN_FILE "LOPEN"
|
|
#define QTEST_V9FS_SYNTH_WRITE_FILE "WRITE"
|
|
|
|
/* for READDIR test */
|
|
#define QTEST_V9FS_SYNTH_READDIR_DIR "ReadDirDir"
|
|
#define QTEST_V9FS_SYNTH_READDIR_FILE "ReadDirFile%d"
|
|
#define QTEST_V9FS_SYNTH_READDIR_NFILES 100
|
|
|
|
/* Any write to the "FLUSH" file is handled one byte at a time by the
|
|
* backend. If the byte is zero, the backend returns success (ie, 1),
|
|
* otherwise it forces the server to try again forever. Thus allowing
|
|
* the client to cancel the request.
|
|
*/
|
|
#define QTEST_V9FS_SYNTH_FLUSH_FILE "FLUSH"
|
|
|
|
#endif
|