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- From 7b6210c5be46e5120b42c09f910e8f104bf3edf1 Mon Sep 17 00:00:00 2001
- From: Erik Larsson <erik@tuxera.com>
- Date: Tue, 13 Jun 2023 17:47:15 +0300
- Subject: [PATCH] unistr.c: Fix use-after-free in 'ntfs_uppercase_mbs'.
- If 'utf8_to_unicode' throws an error due to an invalid UTF-8 sequence,
- then 'n' will be less than 0 and the loop will terminate without storing
- anything in '*t'. After the loop the uppercase string's allocation is
- freed, however after it is freed it is unconditionally accessed through
- '*t', which points into the freed allocation, for the purpose of NULL-
- terminating the string. This leads to a use-after-free.
- Fixed by only NULL-terminating the string when no error has been thrown.
- Thanks for Jeffrey Bencteux for reporting this issue:
- https://github.com/tuxera/ntfs-3g/issues/84
- Upstream-Status: Backport [https://github.com/tuxera/ntfs-3g/commit/75dcdc2cf37478fad6c0e3427403d198b554951d]
- CVE: CVE-2023-52890
- Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
- ---
- libntfs-3g/unistr.c | 3 ++-
- 1 file changed, 2 insertions(+), 1 deletion(-)
- diff --git a/libntfs-3g/unistr.c b/libntfs-3g/unistr.c
- index 5854b3b..db8ddf4 100644
- --- a/libntfs-3g/unistr.c
- +++ b/libntfs-3g/unistr.c
- @@ -1189,8 +1189,9 @@ char *ntfs_uppercase_mbs(const char *low,
- free(upp);
- upp = (char*)NULL;
- errno = EILSEQ;
- + } else {
- + *t = 0;
- }
- - *t = 0;
- }
- return (upp);
- }
- --
- 2.34.1
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