From 524b6c5b39b931311dfe5a2f5abae2f5c9731676 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Sun, 18 Dec 2011 20:09:31 -0800 Subject: sysfs: Kill nlink counting. Tracking the number of subdirectories requires an extra field that increases the size of sysfs_dirent. nlinks are not particularly interesting for sysfs and the nlink counts are wrong when network namespaces are involved so stop counting them, and always return nlink == 1. Userspace already knows that directories with nlink == 1 have an nlink count they can't use to count subdirectories. This reduces the size of sysfs_dirent by 8 bytes on 64bit platforms. Signed-off-by: Eric W. Biederman Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/inode.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'fs/sysfs/inode.c') diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index 4a802b4a905..0ac3e1c1a7d 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -216,9 +216,6 @@ static void sysfs_refresh_inode(struct sysfs_dirent *sd, struct inode *inode) iattrs->ia_secdata, iattrs->ia_secdata_len); } - - if (sysfs_type(sd) == SYSFS_DIR) - set_nlink(inode, sd->s_dir.subdirs + 2); } int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) -- cgit v1.2.3-70-g09d2 From 93518dd2ebafcc761a8637b2877008cfd748c202 Mon Sep 17 00:00:00 2001 From: Masami Ichikawa Date: Tue, 21 Feb 2012 07:43:50 +0900 Subject: sysfs: Fix memory leak in sysfs_sd_setsecdata(). This patch fixies follwing two memory leak patterns that reported by kmemleak. sysfs_sd_setsecdata() is called during sys_lsetxattr() operation. It checks sd->s_iattr is NULL or not. Then if it is NULL, it calls sysfs_init_inode_attrs() to allocate memory. That code is this. iattrs = sd->s_iattr; if (!iattrs) iattrs = sysfs_init_inode_attrs(sd); The iattrs recieves sysfs_init_inode_attrs()'s result, but sd->s_iattr doesn't know the address. so it needs to set correct address to sd->s_iattr to free memory in other function. unreferenced object 0xffff880250b73e60 (size 32): comm "systemd", pid 1, jiffies 4294683888 (age 94.553s) hex dump (first 32 bytes): 73 79 73 74 65 6d 5f 75 3a 6f 62 6a 65 63 74 5f system_u:object_ 72 3a 73 79 73 66 73 5f 74 3a 73 30 00 00 00 00 r:sysfs_t:s0.... backtrace: [] kmemleak_alloc+0x73/0x98 [] __kmalloc+0x100/0x12c [] context_struct_to_string+0x106/0x210 [] security_sid_to_context_core+0x10b/0x129 [] security_sid_to_context+0x10/0x12 [] selinux_inode_getsecurity+0x7d/0xa8 [] selinux_inode_getsecctx+0x22/0x2e [] security_inode_getsecctx+0x16/0x18 [] sysfs_setxattr+0x96/0x117 [] __vfs_setxattr_noperm+0x73/0xd9 [] vfs_setxattr+0x83/0xa1 [] setxattr+0xcf/0x101 [] sys_lsetxattr+0x6a/0x8f [] system_call_fastpath+0x16/0x1b [] 0xffffffffffffffff unreferenced object 0xffff88024163c5a0 (size 96): comm "systemd", pid 1, jiffies 4294683888 (age 94.553s) hex dump (first 32 bytes): 00 00 00 00 ed 41 00 00 00 00 00 00 00 00 00 00 .....A.......... 00 00 00 00 00 00 00 00 0c 64 42 4f 00 00 00 00 .........dBO.... backtrace: [] kmemleak_alloc+0x73/0x98 [] kmem_cache_alloc_trace+0xc4/0xee [] sysfs_init_inode_attrs+0x2a/0x83 [] sysfs_setxattr+0xbf/0x117 [] __vfs_setxattr_noperm+0x73/0xd9 [] vfs_setxattr+0x83/0xa1 [] setxattr+0xcf/0x101 [] sys_lsetxattr+0x6a/0x8f [] system_call_fastpath+0x16/0x1b [] 0xffffffffffffffff ` Signed-off-by: Masami Ichikawa Cc: stable Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/inode.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'fs/sysfs/inode.c') diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index 4291fd1617a..cc7ea5de2fd 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -136,12 +136,13 @@ static int sysfs_sd_setsecdata(struct sysfs_dirent *sd, void **secdata, u32 *sec void *old_secdata; size_t old_secdata_len; - iattrs = sd->s_iattr; - if (!iattrs) - iattrs = sysfs_init_inode_attrs(sd); - if (!iattrs) - return -ENOMEM; + if (!sd->s_iattr) { + sd->s_iattr = sysfs_init_inode_attrs(sd); + if (!sd->s_iattr) + return -ENOMEM; + } + iattrs = sd->s_iattr; old_secdata = iattrs->ia_secdata; old_secdata_len = iattrs->ia_secdata_len; -- cgit v1.2.3-70-g09d2 From 54d20f006ceff1f2f1e69d0e54049b6c0765c039 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 8 Mar 2012 13:03:10 -0800 Subject: Revert "sysfs: Kill nlink counting." This reverts commit 524b6c5b39b931311dfe5a2f5abae2f5c9731676. It has shown to break userspace tools, which is not acceptable. Reported-by: Jiri Slaby Cc: Eric W. Biederman Cc: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 6 ++++++ fs/sysfs/inode.c | 3 +++ fs/sysfs/sysfs.h | 1 + 3 files changed, 10 insertions(+) (limited to 'fs/sysfs/inode.c') diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index dd3779cf3a3..2a7a3f5d1ca 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -91,6 +91,9 @@ static int sysfs_link_sibling(struct sysfs_dirent *sd) struct rb_node **node = &sd->s_parent->s_dir.children.rb_node; struct rb_node *parent = NULL; + if (sysfs_type(sd) == SYSFS_DIR) + sd->s_parent->s_dir.subdirs++; + while (*node) { struct sysfs_dirent *pos; int result; @@ -123,6 +126,9 @@ static int sysfs_link_sibling(struct sysfs_dirent *sd) */ static void sysfs_unlink_sibling(struct sysfs_dirent *sd) { + if (sysfs_type(sd) == SYSFS_DIR) + sd->s_parent->s_dir.subdirs--; + rb_erase(&sd->s_rb, &sd->s_parent->s_dir.children); } diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index cc7ea5de2fd..feb2d69396c 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -217,6 +217,9 @@ static void sysfs_refresh_inode(struct sysfs_dirent *sd, struct inode *inode) iattrs->ia_secdata, iattrs->ia_secdata_len); } + + if (sysfs_type(sd) == SYSFS_DIR) + set_nlink(inode, sd->s_dir.subdirs + 2); } int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 6289a00287d..661a9639570 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -19,6 +19,7 @@ struct sysfs_open_dirent; struct sysfs_elem_dir { struct kobject *kobj; + unsigned long subdirs; /* children rbtree starts here and goes through sd->s_rb */ struct rb_root children; }; -- cgit v1.2.3-70-g09d2