From: Jin Qian jinqian@google.com

partial backport from 21fc61c73c3903c4c312d0802da01ec2b323d174 upstream to v4.4 to prevent virt_to_page on highmem.

ext4_encrypted_follow_link uses kmap() for cpage caddr = kmap(cpage);

_ext4_fname_disk_to_usr calls virt_to_page on the kmapped address. _ext4_fname_disk_to_usr() ext4_fname_decrypt() sg_init_one() sg_init_one(&src_sg, iname->name, iname->len); sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf));

Cc: linux-stable stable@vger.kernel.org # 4.4.y Signed-off-by: Al Viro viro@zeniv.linux.org.uk Signed-off-by: Jin Qian jinqian@google.com Signed-off-by: Jin Qian jinqian@android.com --- fs/ext4/inode.c | 1 + fs/ext4/namei.c | 1 + fs/ext4/symlink.c | 10 +++------- fs/f2fs/inode.c | 1 + fs/f2fs/namei.c | 5 ++--- fs/inode.c | 6 ++++++ include/linux/fs.h | 1 + 7 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 4df1cb19a243..f0cabc8c96cb 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4417,6 +4417,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) inode->i_op = &ext4_symlink_inode_operations; ext4_set_aops(inode); } + inode_nohighmem(inode); } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { inode->i_op = &ext4_special_inode_operations; diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 4c36dca486cc..32960b3ecd4f 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -3151,6 +3151,7 @@ static int ext4_symlink(struct inode *dir, if ((disk_link.len > EXT4_N_BLOCKS * 4)) { if (!encryption_required) inode->i_op = &ext4_symlink_inode_operations; + inode_nohighmem(inode); ext4_set_aops(inode); /* * We cannot call page_symlink() with transaction started diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c index e8e7af62ac95..287c3980fa0b 100644 --- a/fs/ext4/symlink.c +++ b/fs/ext4/symlink.c @@ -45,7 +45,7 @@ static const char *ext4_encrypted_follow_link(struct dentry *dentry, void **cook cpage = read_mapping_page(inode->i_mapping, 0, NULL); if (IS_ERR(cpage)) return ERR_CAST(cpage); - caddr = kmap(cpage); + caddr = page_address(cpage); caddr[size] = 0; }

@@ -75,16 +75,12 @@ static const char *ext4_encrypted_follow_link(struct dentry *dentry, void **cook /* Null-terminate the name */ if (res <= plen) paddr[res] = '\0'; - if (cpage) { - kunmap(cpage); + if (cpage) page_cache_release(cpage); - } return *cookie = paddr; errout: - if (cpage) { - kunmap(cpage); + if (cpage) page_cache_release(cpage); - } kfree(paddr); return ERR_PTR(res); } diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c index 97e20decacb4..5528801a5baf 100644 --- a/fs/f2fs/inode.c +++ b/fs/f2fs/inode.c @@ -202,6 +202,7 @@ make_now: inode->i_op = &f2fs_encrypted_symlink_inode_operations; else inode->i_op = &f2fs_symlink_inode_operations; + inode_nohighmem(inode); inode->i_mapping->a_ops = &f2fs_dblock_aops; } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c index 2c32110f9fc0..484df6850747 100644 --- a/fs/f2fs/namei.c +++ b/fs/f2fs/namei.c @@ -351,6 +351,7 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry, inode->i_op = &f2fs_encrypted_symlink_inode_operations; else inode->i_op = &f2fs_symlink_inode_operations; + inode_nohighmem(inode); inode->i_mapping->a_ops = &f2fs_dblock_aops;

f2fs_lock_op(sbi); @@ -942,7 +943,7 @@ static const char *f2fs_encrypted_follow_link(struct dentry *dentry, void **cook cpage = read_mapping_page(inode->i_mapping, 0, NULL); if (IS_ERR(cpage)) return ERR_CAST(cpage); - caddr = kmap(cpage); + caddr = page_address(cpage); caddr[size] = 0;

/* Symlink is encrypted */ @@ -982,13 +983,11 @@ static const char *f2fs_encrypted_follow_link(struct dentry *dentry, void **cook /* Null-terminate the name */ paddr[res] = '\0';

- kunmap(cpage); page_cache_release(cpage); return *cookie = paddr; errout: kfree(cstr.name); f2fs_fname_crypto_free_buffer(&pstr); - kunmap(cpage); page_cache_release(cpage); return ERR_PTR(res); } diff --git a/fs/inode.c b/fs/inode.c index b0edef500590..b95615f3fc50 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -2028,3 +2028,9 @@ void inode_set_flags(struct inode *inode, unsigned int flags, new_flags) != old_flags)); } EXPORT_SYMBOL(inode_set_flags); + +void inode_nohighmem(struct inode *inode) +{ + mapping_set_gfp_mask(inode->i_mapping, GFP_USER); +} +EXPORT_SYMBOL(inode_nohighmem); diff --git a/include/linux/fs.h b/include/linux/fs.h index c8decb7075d6..f746a59fcc88 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3066,5 +3066,6 @@ static inline bool dir_relax(struct inode *inode) }

extern bool path_noexec(const struct path *path); +extern void inode_nohighmem(struct inode *inode);

#endif /* _LINUX_FS_H */