Commit-ID: a4b3ada83d06554d307dd54abdc62b2e5648264a Gitweb: http://git.kernel.org/tip/a4b3ada83d06554d307dd54abdc62b2e5648264a Author: Carl Henrik Lunde <chlunde@xxxxxxxxxxx> AuthorDate: Fri, 3 Apr 2009 14:27:15 +0200 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Fri, 3 Apr 2009 14:46:22 +0200 blktrace: NUL-terminate user space messages Impact: fix corrupted blkparse output Make sure messages from user space are NUL-terminated strings, otherwise we could dump random memory to the block trace file. Additionally, I've limited the message to BLK_TN_MAX_MSG-1 characters, because the last character would be stripped by vscnprintf anyway. Signed-off-by: Carl Henrik Lunde <chlunde@xxxxxxxxxxx> Cc: Li Zefan <lizf@xxxxxxxxxxxxxx> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Cc: "Alan D. Brunelle" <alan.brunelle@xxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> LKML-Reference: <20090403122714.GT5178@xxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- kernel/trace/blktrace.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 947c5b3..a400b86 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -327,10 +327,10 @@ static ssize_t blk_msg_write(struct file *filp, const char __user *buffer, char *msg; struct blk_trace *bt; - if (count > BLK_TN_MAX_MSG) + if (count > BLK_TN_MAX_MSG - 1) return -EINVAL; - msg = kmalloc(count, GFP_KERNEL); + msg = kmalloc(count + 1, GFP_KERNEL); if (msg == NULL) return -ENOMEM; @@ -339,6 +339,7 @@ static ssize_t blk_msg_write(struct file *filp, const char __user *buffer, return -EFAULT; } + msg[count] = '\0'; bt = filp->private_data; __trace_note_message(bt, "%s", msg); kfree(msg); -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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