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orangefs: cleanup uses of strncpy
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strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

There is some care taken to ensure these destination buffers are
NUL-terminated by bounding the strncpy()'s by ORANGEFS_NAME_MAX - 1 or
ORANGEFS_MAX_SERVER_ADDR_LEN - 1. Instead, we can use the new 2-argument
version of strscpy() to guarantee NUL-termination on the destination
buffers while simplifying the code.

Based on usage with printf-likes, we can see these buffers are expected
to be NUL-terminated:
|	gossip_debug(GOSSIP_NAME_DEBUG,
|			"%s: doing lookup on %s under %pU,%d\n",
|			__func__,
|			new_op->upcall.req.lookup.d_name,
|			&new_op->upcall.req.lookup.parent_refn.khandle,
|			new_op->upcall.req.lookup.parent_refn.fs_id);
...
|	gossip_debug(GOSSIP_SUPER_DEBUG,
|			"Attempting ORANGEFS Remount via host %s\n",
|			new_op->upcall.req.fs_mount.orangefs_config_server);

NUL-padding isn't required for any of these destination buffers as
they've all been zero-allocated with op_alloc() or kzalloc().

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: KSPP#90
Cc: [email protected]
Signed-off-by: Justin Stitt <[email protected]>
Link: https://lore.kernel.org/r/20240322-strncpy-fs-orangefs-dcache-c-v1-1-15d12debbf38@google.com
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>
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@JustinStitt @brauner
JustinStitt authored and brauner committed Apr 9, 2024
1 parent c473bcd commit 6291716
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Showing 3 changed files with 15 additions and 32 deletions.
4 changes: 1 addition & 3 deletions fs/orangefs/dcache.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -33,9 +33,7 @@ static int orangefs_revalidate_lookup(struct dentry *dentry)

new_op->upcall.req.lookup.sym_follow = ORANGEFS_LOOKUP_LINK_NO_FOLLOW;
new_op->upcall.req.lookup.parent_refn = parent->refn;
strncpy(new_op->upcall.req.lookup.d_name,
dentry->d_name.name,
ORANGEFS_NAME_MAX - 1);
strscpy(new_op->upcall.req.lookup.d_name, dentry->d_name.name);

gossip_debug(GOSSIP_DCACHE_DEBUG,
"%s:%s:%d interrupt flag [%d]\n",
Expand Down
26 changes: 8 additions & 18 deletions fs/orangefs/namei.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -41,8 +41,7 @@ static int orangefs_create(struct mnt_idmap *idmap,
fill_default_sys_attrs(new_op->upcall.req.create.attributes,
ORANGEFS_TYPE_METAFILE, mode);

strncpy(new_op->upcall.req.create.d_name,
dentry->d_name.name, ORANGEFS_NAME_MAX - 1);
strscpy(new_op->upcall.req.create.d_name, dentry->d_name.name);

ret = service_operation(new_op, __func__, get_interruptible_flag(dir));

Expand Down Expand Up @@ -137,8 +136,7 @@ static struct dentry *orangefs_lookup(struct inode *dir, struct dentry *dentry,
&parent->refn.khandle);
new_op->upcall.req.lookup.parent_refn = parent->refn;

strncpy(new_op->upcall.req.lookup.d_name, dentry->d_name.name,
ORANGEFS_NAME_MAX - 1);
strscpy(new_op->upcall.req.lookup.d_name, dentry->d_name.name);

gossip_debug(GOSSIP_NAME_DEBUG,
"%s: doing lookup on %s under %pU,%d\n",
Expand Down Expand Up @@ -192,8 +190,7 @@ static int orangefs_unlink(struct inode *dir, struct dentry *dentry)
return -ENOMEM;

new_op->upcall.req.remove.parent_refn = parent->refn;
strncpy(new_op->upcall.req.remove.d_name, dentry->d_name.name,
ORANGEFS_NAME_MAX - 1);
strscpy(new_op->upcall.req.remove.d_name, dentry->d_name.name);

ret = service_operation(new_op, "orangefs_unlink",
get_interruptible_flag(inode));
Expand Down Expand Up @@ -247,10 +244,8 @@ static int orangefs_symlink(struct mnt_idmap *idmap,
ORANGEFS_TYPE_SYMLINK,
mode);

strncpy(new_op->upcall.req.sym.entry_name,
dentry->d_name.name,
ORANGEFS_NAME_MAX - 1);
strncpy(new_op->upcall.req.sym.target, symname, ORANGEFS_NAME_MAX - 1);
strscpy(new_op->upcall.req.sym.entry_name, dentry->d_name.name);
strscpy(new_op->upcall.req.sym.target, symname);

ret = service_operation(new_op, __func__, get_interruptible_flag(dir));

Expand Down Expand Up @@ -324,8 +319,7 @@ static int orangefs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
fill_default_sys_attrs(new_op->upcall.req.mkdir.attributes,
ORANGEFS_TYPE_DIRECTORY, mode);

strncpy(new_op->upcall.req.mkdir.d_name,
dentry->d_name.name, ORANGEFS_NAME_MAX - 1);
strscpy(new_op->upcall.req.mkdir.d_name, dentry->d_name.name);

ret = service_operation(new_op, __func__, get_interruptible_flag(dir));

Expand Down Expand Up @@ -405,12 +399,8 @@ static int orangefs_rename(struct mnt_idmap *idmap,
new_op->upcall.req.rename.old_parent_refn = ORANGEFS_I(old_dir)->refn;
new_op->upcall.req.rename.new_parent_refn = ORANGEFS_I(new_dir)->refn;

strncpy(new_op->upcall.req.rename.d_old_name,
old_dentry->d_name.name,
ORANGEFS_NAME_MAX - 1);
strncpy(new_op->upcall.req.rename.d_new_name,
new_dentry->d_name.name,
ORANGEFS_NAME_MAX - 1);
strscpy(new_op->upcall.req.rename.d_old_name, old_dentry->d_name.name);
strscpy(new_op->upcall.req.rename.d_new_name, new_dentry->d_name.name);

ret = service_operation(new_op,
"orangefs_rename",
Expand Down
17 changes: 6 additions & 11 deletions fs/orangefs/super.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -253,9 +253,8 @@ int orangefs_remount(struct orangefs_sb_info_s *orangefs_sb)
new_op = op_alloc(ORANGEFS_VFS_OP_FS_MOUNT);
if (!new_op)
return -ENOMEM;
strncpy(new_op->upcall.req.fs_mount.orangefs_config_server,
orangefs_sb->devname,
ORANGEFS_MAX_SERVER_ADDR_LEN);
strscpy(new_op->upcall.req.fs_mount.orangefs_config_server,
orangefs_sb->devname);

gossip_debug(GOSSIP_SUPER_DEBUG,
"Attempting ORANGEFS Remount via host %s\n",
Expand Down Expand Up @@ -400,8 +399,7 @@ static int orangefs_unmount(int id, __s32 fs_id, const char *devname)
return -ENOMEM;
op->upcall.req.fs_umount.id = id;
op->upcall.req.fs_umount.fs_id = fs_id;
strncpy(op->upcall.req.fs_umount.orangefs_config_server,
devname, ORANGEFS_MAX_SERVER_ADDR_LEN - 1);
strscpy(op->upcall.req.fs_umount.orangefs_config_server, devname);
r = service_operation(op, "orangefs_fs_umount", 0);
/* Not much to do about an error here. */
if (r)
Expand Down Expand Up @@ -494,9 +492,7 @@ struct dentry *orangefs_mount(struct file_system_type *fst,
if (!new_op)
return ERR_PTR(-ENOMEM);

strncpy(new_op->upcall.req.fs_mount.orangefs_config_server,
devname,
ORANGEFS_MAX_SERVER_ADDR_LEN - 1);
strscpy(new_op->upcall.req.fs_mount.orangefs_config_server, devname);

gossip_debug(GOSSIP_SUPER_DEBUG,
"Attempting ORANGEFS Mount via host %s\n",
Expand Down Expand Up @@ -543,9 +539,8 @@ struct dentry *orangefs_mount(struct file_system_type *fst,
* on successful mount, store the devname and data
* used
*/
strncpy(ORANGEFS_SB(sb)->devname,
devname,
ORANGEFS_MAX_SERVER_ADDR_LEN - 1);
strscpy(ORANGEFS_SB(sb)->devname, devname);


/* mount_pending must be cleared */
ORANGEFS_SB(sb)->mount_pending = 0;
Expand Down

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