From 317b50b8ad2f544a12c8f29d99a91225e8c5db1d Mon Sep 17 00:00:00 2001 From: Andrew Paprocki Date: Mon, 15 Oct 2007 15:43:12 -0400 Subject: [PATCH] libata: prevent devices with blank model names from being DMA blacklisted The strn_pattern_cmp routine does not handle a blank name parameter properly. The only patterns which should match a blank name are "*" and an explicit "". If the function is passed a blank name in current code, it will always match against the patt parameter. The bug manifests itself as the device with the empty model name always matching the first device in the DMA blacklist, forcing it to revert to PIO mode. Signed-off-by: Andrew Paprocki Signed-off-by: Jeff Garzik --- drivers/ata/libata-core.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index d69699973b58..68699b3e7998 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -4014,8 +4014,14 @@ int strn_pattern_cmp(const char *patt, const char *name, int wildchar) p = strchr(patt, wildchar); if (p && ((*(p + 1)) == 0)) len = p - patt; - else + else { len = strlen(name); + if (!len) { + if (!*patt) + return 0; + return -1; + } + } return strncmp(patt, name, len); }