From: Randall Huang <huangrandall@google.com> To: jaegeuk@kernel.org, yuchao0@huawei.com, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Cc: huangrandall@google.com Subject: [PATCH] f2fs: fix to avoid memory leakage in f2fs_listxattr Date: Wed, 9 Oct 2019 11:20:19 +0800 [thread overview] Message-ID: <20191009032019.6954-1-huangrandall@google.com> (raw) In f2fs_listxattr, there is no boundary check before memcpy e_name to buffer. If the e_name_len is corrupted, unexpected memory contents may be returned to the buffer. Signed-off-by: Randall Huang <huangrandall@google.com> --- fs/f2fs/xattr.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c index b32c45621679..acc3663970cd 100644 --- a/fs/f2fs/xattr.c +++ b/fs/f2fs/xattr.c @@ -538,8 +538,9 @@ int f2fs_getxattr(struct inode *inode, int index, const char *name, ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) { struct inode *inode = d_inode(dentry); + nid_t xnid = F2FS_I(inode)->i_xattr_nid; struct f2fs_xattr_entry *entry; - void *base_addr; + void *base_addr, *last_base_addr; int error = 0; size_t rest = buffer_size; @@ -549,6 +550,8 @@ ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) if (error) return error; + last_base_addr = (void *)base_addr + XATTR_SIZE(xnid, inode); + list_for_each_xattr(entry, base_addr) { const struct xattr_handler *handler = f2fs_xattr_handler(entry->e_name_index); @@ -559,6 +562,15 @@ ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) if (!handler || (handler->list && !handler->list(dentry))) continue; + if ((void *)(entry) + sizeof(__u32) > last_base_addr || + (void *)XATTR_NEXT_ENTRY(entry) > last_base_addr) { + f2fs_err(F2FS_I_SB(inode), "inode (%lu) has corrupted xattr", + inode->i_ino); + set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_FSCK); + error = -EFSCORRUPTED; + goto cleanup; + } + prefix = xattr_prefix(handler); prefix_len = strlen(prefix); size = prefix_len + entry->e_name_len + 1; -- 2.23.0.581.g78d2f28ef7-goog
WARNING: multiple messages have this Message-ID (diff)
From: Randall Huang via Linux-f2fs-devel <linux-f2fs-devel@lists.sourceforge.net> To: jaegeuk@kernel.org, yuchao0@huawei.com, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: [f2fs-dev] [PATCH] f2fs: fix to avoid memory leakage in f2fs_listxattr Date: Wed, 9 Oct 2019 11:20:19 +0800 [thread overview] Message-ID: <20191009032019.6954-1-huangrandall@google.com> (raw) In f2fs_listxattr, there is no boundary check before memcpy e_name to buffer. If the e_name_len is corrupted, unexpected memory contents may be returned to the buffer. Signed-off-by: Randall Huang <huangrandall@google.com> --- fs/f2fs/xattr.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c index b32c45621679..acc3663970cd 100644 --- a/fs/f2fs/xattr.c +++ b/fs/f2fs/xattr.c @@ -538,8 +538,9 @@ int f2fs_getxattr(struct inode *inode, int index, const char *name, ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) { struct inode *inode = d_inode(dentry); + nid_t xnid = F2FS_I(inode)->i_xattr_nid; struct f2fs_xattr_entry *entry; - void *base_addr; + void *base_addr, *last_base_addr; int error = 0; size_t rest = buffer_size; @@ -549,6 +550,8 @@ ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) if (error) return error; + last_base_addr = (void *)base_addr + XATTR_SIZE(xnid, inode); + list_for_each_xattr(entry, base_addr) { const struct xattr_handler *handler = f2fs_xattr_handler(entry->e_name_index); @@ -559,6 +562,15 @@ ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) if (!handler || (handler->list && !handler->list(dentry))) continue; + if ((void *)(entry) + sizeof(__u32) > last_base_addr || + (void *)XATTR_NEXT_ENTRY(entry) > last_base_addr) { + f2fs_err(F2FS_I_SB(inode), "inode (%lu) has corrupted xattr", + inode->i_ino); + set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_FSCK); + error = -EFSCORRUPTED; + goto cleanup; + } + prefix = xattr_prefix(handler); prefix_len = strlen(prefix); size = prefix_len + entry->e_name_len + 1; -- 2.23.0.581.g78d2f28ef7-goog _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
next reply other threads:[~2019-10-09 3:20 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-10-09 3:20 Randall Huang [this message] 2019-10-09 3:20 ` [f2fs-dev] [PATCH] f2fs: fix to avoid memory leakage in f2fs_listxattr Randall Huang via Linux-f2fs-devel 2019-10-15 7:22 ` Chao Yu 2019-10-15 7:22 ` [f2fs-dev] " Chao Yu 2019-10-18 6:56 ` [PATCH v2] " Randall Huang 2019-10-18 6:56 ` [f2fs-dev] " Randall Huang via Linux-f2fs-devel 2019-10-22 8:35 ` Chao Yu 2019-10-22 8:35 ` [f2fs-dev] " Chao Yu
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