From 0e5cc9a40ada6046e6bc3bdfcd0c0d7e4b706b14 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Thu, 18 Dec 2014 22:37:50 +0100 Subject: udf: Check path length when reading symlink Symlink reading code does not check whether the resulting path fits into the page provided by the generic code. This isn't as easy as just checking the symlink size because of various encoding conversions we perform on path. So we have to check whether there is still enough space in the buffer on the fly. CC: stable@vger.kernel.org Reported-by: Carl Henrik Lunde Signed-off-by: Jan Kara --- fs/udf/unicode.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) (limited to 'fs/udf/unicode.c') diff --git a/fs/udf/unicode.c b/fs/udf/unicode.c index afd470e588ff..b84fee372734 100644 --- a/fs/udf/unicode.c +++ b/fs/udf/unicode.c @@ -28,7 +28,8 @@ #include "udf_sb.h" -static int udf_translate_to_linux(uint8_t *, uint8_t *, int, uint8_t *, int); +static int udf_translate_to_linux(uint8_t *, int, uint8_t *, int, uint8_t *, + int); static int udf_char_to_ustr(struct ustr *dest, const uint8_t *src, int strlen) { @@ -333,8 +334,8 @@ try_again: return u_len + 1; } -int udf_get_filename(struct super_block *sb, uint8_t *sname, uint8_t *dname, - int flen) +int udf_get_filename(struct super_block *sb, uint8_t *sname, int slen, + uint8_t *dname, int dlen) { struct ustr *filename, *unifilename; int len = 0; @@ -347,7 +348,7 @@ int udf_get_filename(struct super_block *sb, uint8_t *sname, uint8_t *dname, if (!unifilename) goto out1; - if (udf_build_ustr_exact(unifilename, sname, flen)) + if (udf_build_ustr_exact(unifilename, sname, slen)) goto out2; if (UDF_QUERY_FLAG(sb, UDF_FLAG_UTF8)) { @@ -366,7 +367,8 @@ int udf_get_filename(struct super_block *sb, uint8_t *sname, uint8_t *dname, } else goto out2; - len = udf_translate_to_linux(dname, filename->u_name, filename->u_len, + len = udf_translate_to_linux(dname, dlen, + filename->u_name, filename->u_len, unifilename->u_name, unifilename->u_len); out2: kfree(unifilename); @@ -403,10 +405,12 @@ int udf_put_filename(struct super_block *sb, const uint8_t *sname, #define EXT_MARK '.' #define CRC_MARK '#' #define EXT_SIZE 5 +/* Number of chars we need to store generated CRC to make filename unique */ +#define CRC_LEN 5 -static int udf_translate_to_linux(uint8_t *newName, uint8_t *udfName, - int udfLen, uint8_t *fidName, - int fidNameLen) +static int udf_translate_to_linux(uint8_t *newName, int newLen, + uint8_t *udfName, int udfLen, + uint8_t *fidName, int fidNameLen) { int index, newIndex = 0, needsCRC = 0; int extIndex = 0, newExtIndex = 0, hasExt = 0; @@ -439,7 +443,7 @@ static int udf_translate_to_linux(uint8_t *newName, uint8_t *udfName, newExtIndex = newIndex; } } - if (newIndex < 256) + if (newIndex < newLen) newName[newIndex++] = curr; else needsCRC = 1; @@ -467,13 +471,13 @@ static int udf_translate_to_linux(uint8_t *newName, uint8_t *udfName, } ext[localExtIndex++] = curr; } - maxFilenameLen = 250 - localExtIndex; + maxFilenameLen = newLen - CRC_LEN - localExtIndex; if (newIndex > maxFilenameLen) newIndex = maxFilenameLen; else newIndex = newExtIndex; - } else if (newIndex > 250) - newIndex = 250; + } else if (newIndex > newLen - CRC_LEN) + newIndex = newLen - CRC_LEN; newName[newIndex++] = CRC_MARK; valueCRC = crc_itu_t(0, fidName, fidNameLen); newName[newIndex++] = hex_asc_upper_hi(valueCRC >> 8); -- cgit v1.2.3-55-g7522