From 5f3ef64f4da1c587cdcfaaac72311225b7df094c Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Wed, 14 Oct 2009 16:18:27 -0500 Subject: [PATCH 01/10] eCryptfs: Use notify_change for truncating lower inodes When truncating inodes in the lower filesystem, eCryptfs directly invoked vmtruncate(). As Christoph Hellwig pointed out, vmtruncate() is a filesystem helper function, but filesystems may need to do more than just a call to vmtruncate(). This patch moves the lower inode truncation out of ecryptfs_truncate() and renames the function to truncate_upper(). truncate_upper() updates an iattr for the lower inode to indicate if the lower inode needs to be truncated upon return. ecryptfs_setattr() then calls notify_change(), using the updated iattr for the lower inode, to complete the truncation. For eCryptfs functions needing to truncate, ecryptfs_truncate() is reintroduced as a simple way to truncate the upper inode to a specified size and then truncate the lower inode accordingly. https://bugs.launchpad.net/bugs/451368 Reported-by: Christoph Hellwig Acked-by: Dustin Kirkland Cc: ecryptfs-devel@lists.launchpad.net Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Tyler Hicks --- fs/ecryptfs/inode.c | 99 ++++++++++++++++++++++++++++++--------------- 1 file changed, 67 insertions(+), 32 deletions(-) diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 7f8545032930..2b449d79b7fa 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -772,18 +772,23 @@ upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat, } /** - * ecryptfs_truncate + * truncate_upper * @dentry: The ecryptfs layer dentry - * @new_length: The length to expand the file to + * @ia: Address of the ecryptfs inode's attributes + * @lower_ia: Address of the lower inode's attributes * * Function to handle truncations modifying the size of the file. Note * that the file sizes are interpolated. When expanding, we are simply - * writing strings of 0's out. When truncating, we need to modify the - * underlying file size according to the page index interpolations. + * writing strings of 0's out. When truncating, we truncate the upper + * inode and update the lower_ia according to the page index + * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return, + * the caller must use lower_ia in a call to notify_change() to perform + * the truncation of the lower inode. * * Returns zero on success; non-zero otherwise */ -int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) +static int truncate_upper(struct dentry *dentry, struct iattr *ia, + struct iattr *lower_ia) { int rc = 0; struct inode *inode = dentry->d_inode; @@ -794,8 +799,10 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) loff_t lower_size_before_truncate; loff_t lower_size_after_truncate; - if (unlikely((new_length == i_size))) + if (unlikely((ia->ia_size == i_size))) { + lower_ia->ia_valid &= ~ATTR_SIZE; goto out; + } crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat; /* Set up a fake ecryptfs file, this is used to interface with * the file in the underlying filesystem so that the @@ -815,28 +822,30 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) &fake_ecryptfs_file, ecryptfs_inode_to_private(dentry->d_inode)->lower_file); /* Switch on growing or shrinking file */ - if (new_length > i_size) { + if (ia->ia_size > i_size) { char zero[] = { 0x00 }; + lower_ia->ia_valid &= ~ATTR_SIZE; /* Write a single 0 at the last position of the file; * this triggers code that will fill in 0's throughout * the intermediate portion of the previous end of the * file and the new and of the file */ rc = ecryptfs_write(&fake_ecryptfs_file, zero, - (new_length - 1), 1); - } else { /* new_length < i_size_read(inode) */ - /* We're chopping off all the pages down do the page - * in which new_length is located. Fill in the end of - * that page from (new_length & ~PAGE_CACHE_MASK) to + (ia->ia_size - 1), 1); + } else { /* ia->ia_size < i_size_read(inode) */ + /* We're chopping off all the pages down to the page + * in which ia->ia_size is located. Fill in the end of + * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to * PAGE_CACHE_SIZE with zeros. */ size_t num_zeros = (PAGE_CACHE_SIZE - - (new_length & ~PAGE_CACHE_MASK)); + - (ia->ia_size & ~PAGE_CACHE_MASK)); if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { - rc = vmtruncate(inode, new_length); + rc = vmtruncate(inode, ia->ia_size); if (rc) goto out_free; - rc = vmtruncate(lower_dentry->d_inode, new_length); + lower_ia->ia_size = ia->ia_size; + lower_ia->ia_valid |= ATTR_SIZE; goto out_free; } if (num_zeros) { @@ -848,7 +857,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) goto out_free; } rc = ecryptfs_write(&fake_ecryptfs_file, zeros_virt, - new_length, num_zeros); + ia->ia_size, num_zeros); kfree(zeros_virt); if (rc) { printk(KERN_ERR "Error attempting to zero out " @@ -857,7 +866,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) goto out_free; } } - vmtruncate(inode, new_length); + vmtruncate(inode, ia->ia_size); rc = ecryptfs_write_inode_size_to_metadata(inode); if (rc) { printk(KERN_ERR "Problem with " @@ -870,10 +879,12 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) lower_size_before_truncate = upper_size_to_lower_size(crypt_stat, i_size); lower_size_after_truncate = - upper_size_to_lower_size(crypt_stat, new_length); - if (lower_size_after_truncate < lower_size_before_truncate) - vmtruncate(lower_dentry->d_inode, - lower_size_after_truncate); + upper_size_to_lower_size(crypt_stat, ia->ia_size); + if (lower_size_after_truncate < lower_size_before_truncate) { + lower_ia->ia_size = lower_size_after_truncate; + lower_ia->ia_valid |= ATTR_SIZE; + } else + lower_ia->ia_valid &= ~ATTR_SIZE; } out_free: if (ecryptfs_file_to_private(&fake_ecryptfs_file)) @@ -883,6 +894,33 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) return rc; } +/** + * ecryptfs_truncate + * @dentry: The ecryptfs layer dentry + * @new_length: The length to expand the file to + * + * Simple function that handles the truncation of an eCryptfs inode and + * its corresponding lower inode. + * + * Returns zero on success; non-zero otherwise + */ +int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) +{ + struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length }; + struct iattr lower_ia = { .ia_valid = 0 }; + int rc; + + rc = truncate_upper(dentry, &ia, &lower_ia); + if (!rc && lower_ia.ia_valid & ATTR_SIZE) { + struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry); + + mutex_lock(&lower_dentry->d_inode->i_mutex); + rc = notify_change(lower_dentry, &lower_ia); + mutex_unlock(&lower_dentry->d_inode->i_mutex); + } + return rc; +} + static int ecryptfs_permission(struct inode *inode, int mask) { @@ -905,6 +943,7 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia) { int rc = 0; struct dentry *lower_dentry; + struct iattr lower_ia; struct inode *inode; struct inode *lower_inode; struct ecryptfs_crypt_stat *crypt_stat; @@ -943,15 +982,11 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia) } } mutex_unlock(&crypt_stat->cs_mutex); + memcpy(&lower_ia, ia, sizeof(lower_ia)); + if (ia->ia_valid & ATTR_FILE) + lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file); if (ia->ia_valid & ATTR_SIZE) { - ecryptfs_printk(KERN_DEBUG, - "ia->ia_valid = [0x%x] ATTR_SIZE" " = [0x%x]\n", - ia->ia_valid, ATTR_SIZE); - rc = ecryptfs_truncate(dentry, ia->ia_size); - /* ecryptfs_truncate handles resizing of the lower file */ - ia->ia_valid &= ~ATTR_SIZE; - ecryptfs_printk(KERN_DEBUG, "ia->ia_valid = [%x]\n", - ia->ia_valid); + rc = truncate_upper(dentry, ia, &lower_ia); if (rc < 0) goto out; } @@ -960,11 +995,11 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia) * mode change is for clearing setuid/setgid bits. Allow lower fs * to interpret this in its own way. */ - if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID)) - ia->ia_valid &= ~ATTR_MODE; + if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID)) + lower_ia.ia_valid &= ~ATTR_MODE; mutex_lock(&lower_dentry->d_inode->i_mutex); - rc = notify_change(lower_dentry, ia); + rc = notify_change(lower_dentry, &lower_ia); mutex_unlock(&lower_dentry->d_inode->i_mutex); out: fsstack_copy_attr_all(inode, lower_inode); From f8f484d1b6677dd5cd5e7e605db747e8c30bbd47 Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Wed, 4 Nov 2009 02:48:01 -0600 Subject: [PATCH 02/10] eCryptfs: Add getattr function MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The i_blocks field of an eCryptfs inode cannot be trusted, but generic_fillattr() uses it to instantiate the blocks field of a stat() syscall when a filesystem doesn't implement its own getattr(). Users have noticed that the output of du is incorrect on newly created files. This patch creates ecryptfs_getattr() which calls into the lower filesystem's getattr() so that eCryptfs can use its kstat.blocks value after calling generic_fillattr(). It is important to note that the block count includes the eCryptfs metadata stored in the beginning of the lower file plus any padding used to fill an extent before encryption. https://bugs.launchpad.net/ecryptfs/+bug/390833 Reported-by: Dominic Sacré Signed-off-by: Tyler Hicks --- fs/ecryptfs/inode.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 2b449d79b7fa..5726d7adaf5b 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -1006,6 +1006,21 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia) return rc; } +int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry, + struct kstat *stat) +{ + struct kstat lower_stat; + int rc; + + rc = vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry), + ecryptfs_dentry_to_lower(dentry), &lower_stat); + if (!rc) { + generic_fillattr(dentry->d_inode, stat); + stat->blocks = lower_stat.blocks; + } + return rc; +} + int ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) @@ -1135,6 +1150,7 @@ const struct inode_operations ecryptfs_dir_iops = { const struct inode_operations ecryptfs_main_iops = { .permission = ecryptfs_permission, .setattr = ecryptfs_setattr, + .getattr = ecryptfs_getattr, .setxattr = ecryptfs_setxattr, .getxattr = ecryptfs_getxattr, .listxattr = ecryptfs_listxattr, From 38e3eaeedcac75360af8a92e7b66956ec4f334e5 Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Tue, 3 Nov 2009 14:56:06 -0600 Subject: [PATCH 03/10] eCryptfs: Remove mmap from directory operations Adrian reported that mkfontscale didn't work inside of eCryptfs mounts. Strace revealed the following: open("./", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_DIRECTORY|O_CLOEXEC) = 3 fcntl64(3, F_GETFD) = 0x1 (flags FD_CLOEXEC) open("./fonts.scale", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 4 getdents(3, /* 80 entries */, 32768) = 2304 open("./.", O_RDONLY) = 5 fcntl64(5, F_SETFD, FD_CLOEXEC) = 0 fstat64(5, {st_mode=S_IFDIR|0755, st_size=16384, ...}) = 0 mmap2(NULL, 16384, PROT_READ, MAP_PRIVATE, 5, 0) = 0xb7fcf000 close(5) = 0 --- SIGBUS (Bus error) @ 0 (0) --- +++ killed by SIGBUS +++ The mmap2() on a directory was successful, resulting in a SIGBUS signal later. This patch removes mmap() from the list of possible ecryptfs_dir_fops so that mmap() isn't possible on eCryptfs directory files. https://bugs.launchpad.net/ecryptfs/+bug/400443 Reported-by: Adrian C. Signed-off-by: Tyler Hicks --- fs/ecryptfs/file.c | 1 - 1 file changed, 1 deletion(-) diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c index 9e944057001b..3efc7fdc3c39 100644 --- a/fs/ecryptfs/file.c +++ b/fs/ecryptfs/file.c @@ -299,7 +299,6 @@ static int ecryptfs_ioctl(struct inode *inode, struct file *file, const struct file_operations ecryptfs_dir_fops = { .readdir = ecryptfs_readdir, .ioctl = ecryptfs_ioctl, - .mmap = generic_file_mmap, .open = ecryptfs_open, .flush = ecryptfs_flush, .release = ecryptfs_release, From e27759d7a333d1f25d628c4f7caf845c51be51c2 Mon Sep 17 00:00:00 2001 From: Erez Zadok Date: Thu, 3 Dec 2009 13:35:27 -0500 Subject: [PATCH 04/10] ecryptfs: initialize private persistent file before dereferencing pointer Ecryptfs_open dereferences a pointer to the private lower file (the one stored in the ecryptfs inode), without checking if the pointer is NULL. Right afterward, it initializes that pointer if it is NULL. Swap order of statements to first initialize. Bug discovered by Duckjin Kang. Signed-off-by: Duckjin Kang Signed-off-by: Erez Zadok Cc: Dustin Kirkland Cc: Al Viro Cc: Signed-off-by: Tyler Hicks --- fs/ecryptfs/file.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c index 3efc7fdc3c39..dde7bb48bb5f 100644 --- a/fs/ecryptfs/file.c +++ b/fs/ecryptfs/file.c @@ -191,13 +191,6 @@ static int ecryptfs_open(struct inode *inode, struct file *file) | ECRYPTFS_ENCRYPTED); } mutex_unlock(&crypt_stat->cs_mutex); - if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_RDONLY) - && !(file->f_flags & O_RDONLY)) { - rc = -EPERM; - printk(KERN_WARNING "%s: Lower persistent file is RO; eCryptfs " - "file must hence be opened RO\n", __func__); - goto out; - } if (!ecryptfs_inode_to_private(inode)->lower_file) { rc = ecryptfs_init_persistent_file(ecryptfs_dentry); if (rc) { @@ -208,6 +201,13 @@ static int ecryptfs_open(struct inode *inode, struct file *file) goto out; } } + if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_RDONLY) + && !(file->f_flags & O_RDONLY)) { + rc = -EPERM; + printk(KERN_WARNING "%s: Lower persistent file is RO; eCryptfs " + "file must hence be opened RO\n", __func__); + goto out; + } ecryptfs_set_file_lower( file, ecryptfs_inode_to_private(inode)->lower_file); if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) { From 0d132f7364694da8f7cafd49e2fc2721b73e96e4 Mon Sep 17 00:00:00 2001 From: Erez Zadok Date: Sat, 5 Dec 2009 21:17:09 -0500 Subject: [PATCH 05/10] ecryptfs: don't ignore return value from lock_rename Signed-off-by: Erez Zadok Cc: Dustin Kirkland Cc: Andrew Morton Cc: Al Viro Signed-off-by: Tyler Hicks --- fs/ecryptfs/inode.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 5726d7adaf5b..764dc777b268 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -614,6 +614,7 @@ ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry, struct dentry *lower_new_dentry; struct dentry *lower_old_dir_dentry; struct dentry *lower_new_dir_dentry; + struct dentry *trap = NULL; lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry); lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry); @@ -621,7 +622,17 @@ ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry, dget(lower_new_dentry); lower_old_dir_dentry = dget_parent(lower_old_dentry); lower_new_dir_dentry = dget_parent(lower_new_dentry); - lock_rename(lower_old_dir_dentry, lower_new_dir_dentry); + trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry); + /* source should not be ancestor of target */ + if (trap == lower_old_dentry) { + rc = -EINVAL; + goto out_lock; + } + /* target should not be ancestor of source */ + if (trap == lower_new_dentry) { + rc = -ENOTEMPTY; + goto out_lock; + } rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry, lower_new_dir_dentry->d_inode, lower_new_dentry); if (rc) From c44a66d674688f1e1d0b2f6f56bd9c6a1b061cae Mon Sep 17 00:00:00 2001 From: Erez Zadok Date: Sun, 6 Dec 2009 18:05:30 -0500 Subject: [PATCH 06/10] ecryptfs: remove unnecessary d_drop calls in ecryptfs_link Unnecessary because it would unhash perfectly valid dentries, causing them to have to be re-looked up the next time they're needed, which presumably is right after. Signed-off-by: Aseem Rastogi Signed-off-by: Shrikar archak Signed-off-by: Erez Zadok Cc: Saumitra Bhanage Cc: Al Viro Signed-off-by: Tyler Hicks --- fs/ecryptfs/inode.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 764dc777b268..e03415293625 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -463,9 +463,6 @@ static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir, unlock_dir(lower_dir_dentry); dput(lower_new_dentry); dput(lower_old_dentry); - d_drop(lower_old_dentry); - d_drop(new_dentry); - d_drop(old_dentry); return rc; } From 3469b57329f80db5a41cf42d1c8f7690269f57e7 Mon Sep 17 00:00:00 2001 From: Erez Zadok Date: Sun, 6 Dec 2009 18:51:15 -0500 Subject: [PATCH 07/10] ecryptfs: pass matching flags to interpose as defined and used there ecryptfs_interpose checks if one of the flags passed is ECRYPTFS_INTERPOSE_FLAG_D_ADD, defined as 0x00000001 in ecryptfs_kernel.h. But the only user of ecryptfs_interpose to pass a non-zero flag to it, has hard-coded the value as "1". This could spell trouble if any of these values changes in the future. Signed-off-by: Erez Zadok Cc: Dustin Kirkland Cc: Al Viro Signed-off-by: Tyler Hicks --- fs/ecryptfs/inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index e03415293625..4a430ab4115c 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -282,7 +282,8 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry, goto out; } rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry, - ecryptfs_dir_inode->i_sb, 1); + ecryptfs_dir_inode->i_sb, + ECRYPTFS_INTERPOSE_FLAG_D_ADD); if (rc) { printk(KERN_ERR "%s: Error interposing; rc = [%d]\n", __func__, rc); From fe0fc013cd8bbd2f4737c1b2694b37dd7fe459cb Mon Sep 17 00:00:00 2001 From: Erez Zadok Date: Mon, 4 Jan 2010 18:17:02 -0500 Subject: [PATCH 08/10] ecryptfs: fix interpose/interpolate typos in comments Signed-off-by: Erez Zadok Acked-by: Dustin Kirkland Signed-off-by: Tyler Hicks --- fs/ecryptfs/main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c index 567bc4b9f70a..ea2f92101dfe 100644 --- a/fs/ecryptfs/main.c +++ b/fs/ecryptfs/main.c @@ -585,8 +585,8 @@ static int ecryptfs_read_super(struct super_block *sb, const char *dev_name) * with as much information as it can before needing * the lower filesystem. * ecryptfs_read_super(): this accesses the lower filesystem and uses - * ecryptfs_interpolate to perform most of the linking - * ecryptfs_interpolate(): links the lower filesystem into ecryptfs + * ecryptfs_interpose to perform most of the linking + * ecryptfs_interpose(): links the lower filesystem into ecryptfs (inode.c) */ static int ecryptfs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *raw_data, From 4aa25bcb7dac2d583f1557e2be2d0b598581da54 Mon Sep 17 00:00:00 2001 From: Julia Lawall Date: Sat, 16 Jan 2010 17:00:26 +0100 Subject: [PATCH 09/10] ecryptfs: Eliminate useless code The variable lower_dentry is initialized twice to the same (side effect-free) expression. Drop one initialization. A simplified version of the semantic match that finds this problem is: (http://coccinelle.lip6.fr/) // @forall@ idexpression *x; identifier f!=ERR_PTR; @@ x = f(...) ... when != x ( x = f(...,<+...x...+>,...) | * x = f(...) ) // Signed-off-by: Julia Lawall Signed-off-by: Tyler Hicks --- fs/ecryptfs/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c index dde7bb48bb5f..678172b61be2 100644 --- a/fs/ecryptfs/file.c +++ b/fs/ecryptfs/file.c @@ -158,7 +158,7 @@ static int ecryptfs_open(struct inode *inode, struct file *file) struct dentry *ecryptfs_dentry = file->f_path.dentry; /* Private value of ecryptfs_dentry allocated in * ecryptfs_lookup() */ - struct dentry *lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); + struct dentry *lower_dentry; struct ecryptfs_file_info *file_info; mount_crypt_stat = &ecryptfs_superblock_to_private( From ece550f51ba175c14ec3ec047815927d7386ea1f Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 19 Jan 2010 12:34:32 +0300 Subject: [PATCH 10/10] ecryptfs: use after free The "full_alg_name" variable is used on a couple error paths, so we shouldn't free it until the end. Signed-off-by: Dan Carpenter Cc: stable@kernel.org Signed-off-by: Tyler Hicks --- fs/ecryptfs/crypto.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index fbb6e5eed697..7cb0a59f4b9d 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -1748,7 +1748,7 @@ ecryptfs_process_key_cipher(struct crypto_blkcipher **key_tfm, char *cipher_name, size_t *key_size) { char dummy_key[ECRYPTFS_MAX_KEY_BYTES]; - char *full_alg_name; + char *full_alg_name = NULL; int rc; *key_tfm = NULL; @@ -1763,7 +1763,6 @@ ecryptfs_process_key_cipher(struct crypto_blkcipher **key_tfm, if (rc) goto out; *key_tfm = crypto_alloc_blkcipher(full_alg_name, 0, CRYPTO_ALG_ASYNC); - kfree(full_alg_name); if (IS_ERR(*key_tfm)) { rc = PTR_ERR(*key_tfm); printk(KERN_ERR "Unable to allocate crypto cipher with name " @@ -1786,6 +1785,7 @@ ecryptfs_process_key_cipher(struct crypto_blkcipher **key_tfm, goto out; } out: + kfree(full_alg_name); return rc; }