From dc74eaad8cda9f12a885639b4f2513c99e9b483a Mon Sep 17 00:00:00 2001 From: Lachlan McIlroy Date: Sat, 10 Feb 2007 18:34:38 +1100 Subject: [XFS] Prevent buffer overrun in cmn_err(). The message buffer used by cmn_err() is only 256 bytes and some CXFS messages were exceeding this length. Since we were using vsprintf() and not checking for buffer overruns we were clobbering memory beyond the buffer. The size of the buffer has been increased to 1024 bytes so we can capture these larger messages and we are now using vsnprintf() to prevent overrunning the buffer size. SGI-PV: 958599 SGI-Modid: xfs-linux-melb:xfs-kern:27561a Signed-off-by: Lachlan McIlroy Signed-off-by: Geoffrey Wehrman Signed-off-by: Tim Shimmin --- fs/xfs/support/debug.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) (limited to 'fs/xfs') diff --git a/fs/xfs/support/debug.c b/fs/xfs/support/debug.c index 4363512d2f90..08bbd3cb87ae 100644 --- a/fs/xfs/support/debug.c +++ b/fs/xfs/support/debug.c @@ -19,7 +19,7 @@ #include "debug.h" #include "spin.h" -static char message[256]; /* keep it off the stack */ +static char message[1024]; /* keep it off the stack */ static DEFINE_SPINLOCK(xfs_err_lock); /* Translate from CE_FOO to KERN_FOO, err_level(CE_FOO) == KERN_FOO */ @@ -44,13 +44,14 @@ cmn_err(register int level, char *fmt, ...) spin_lock_irqsave(&xfs_err_lock,flags); va_start(ap, fmt); if (*fmt == '!') fp++; - len = vsprintf(message, fp, ap); - if (level != CE_DEBUG && message[len-1] != '\n') - strcat(message, "\n"); - printk("%s%s", err_level[level], message); + len = vsnprintf(message, sizeof(message), fp, ap); + if (len >= sizeof(message)) + len = sizeof(message) - 1; + if (message[len-1] == '\n') + message[len-1] = 0; + printk("%s%s\n", err_level[level], message); va_end(ap); spin_unlock_irqrestore(&xfs_err_lock,flags); - BUG_ON(level == CE_PANIC); } @@ -64,11 +65,13 @@ icmn_err(register int level, char *fmt, va_list ap) if(level > XFS_MAX_ERR_LEVEL) level = XFS_MAX_ERR_LEVEL; spin_lock_irqsave(&xfs_err_lock,flags); - len = vsprintf(message, fmt, ap); - if (level != CE_DEBUG && message[len-1] != '\n') - strcat(message, "\n"); + len = vsnprintf(message, sizeof(message), fmt, ap); + if (len >= sizeof(message)) + len = sizeof(message) - 1; + if (message[len-1] == '\n') + message[len-1] = 0; + printk("%s%s\n", err_level[level], message); spin_unlock_irqrestore(&xfs_err_lock,flags); - printk("%s%s", err_level[level], message); BUG_ON(level == CE_PANIC); } -- cgit v1.2.1