Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 4.18 03/39] cifs: fix return value for cifs_listxattr | Date | Tue, 13 Nov 2018 00:50:17 -0500 |
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From: Ronnie Sahlberg <lsahlber@redhat.com>
[ Upstream commit 0c5d6cb6643f48ad3775322f3ebab6c7eb67484e ]
If the application buffer was too small to fit all the names we would still count the number of bytes and return this for listxattr. This would then trigger a BUG in usercopy.c
Fix the computation of the size so that we return -ERANGE correctly when the buffer is too small.
This fixes the kernel BUG for xfstest generic/377
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org> --- fs/cifs/smb2ops.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index abb54b852bdc..bf68e4658dc4 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -682,6 +682,7 @@ move_smb2_ea_to_cifs(char *dst, size_t dst_size, int rc = 0; unsigned int ea_name_len = ea_name ? strlen(ea_name) : 0; char *name, *value; + size_t buf_size = dst_size; size_t name_len, value_len, user_name_len; while (src_size > 0) { @@ -717,9 +718,10 @@ move_smb2_ea_to_cifs(char *dst, size_t dst_size, /* 'user.' plus a terminating null */ user_name_len = 5 + 1 + name_len; - rc += user_name_len; - - if (dst_size >= user_name_len) { + if (buf_size == 0) { + /* skip copy - calc size only */ + rc += user_name_len; + } else if (dst_size >= user_name_len) { dst_size -= user_name_len; memcpy(dst, "user.", 5); dst += 5; @@ -727,8 +729,7 @@ move_smb2_ea_to_cifs(char *dst, size_t dst_size, dst += name_len; *dst = 0; ++dst; - } else if (dst_size == 0) { - /* skip copy - calc size only */ + rc += user_name_len; } else { /* stop before overrun buffer */ rc = -ERANGE; -- 2.17.1
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