Messages in this thread Patch in this message | | | Subject | [bug+patch] negative inode number in /proc/net/udp | From | Arnaud Giersch <> | Date | 18 Feb 2002 16:16:58 +0100 |
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Hi,
I was playing this morning with the netstat command and had a segfault when doing `netstat -ulp'. My kernel version is 2.4.17 on an i686.
I first searched for a bug in netstat and I discovered that it was a negative inode number in /proc/net/udp that confused netstat:
$ cat /proc/net/udp sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode [...] 80: 00000000:02D0 00000000:0000 07 00000000:00000000 00:00000000 00000000 0 0 -2127935727 2 ca5dd060 [...]
(Before continuing, I want to tell you that it is the first time I look so precisely in the kernel source so please tell me if I'm wrong or I missed something.)
If I understand the kernel source, an inode number is an unsigned value ("typedef unsigned long __kernel_ino_t;" in linux/include/asm-i386/posix_types.h) so it shouldn't be negative.
I tried to find where /proc/net/udp is created and I found the function get_udp_sock in linux/net/ipv4/udp.c responsible of generating the lines.
There, the sprintf call uses %ld instead of %lu to print the inode number. I propose the following patch:
diff -Naur linux.orig/net/ipv4/udp.c linux/net/ipv4/udp.c --- linux.orig/net/ipv4/udp.c Wed Oct 17 23:16:39 2001 +++ linux/net/ipv4/udp.c Mon Feb 18 15:49:49 2002 @@ -957,7 +957,7 @@ destp = ntohs(sp->dport); srcp = ntohs(sp->sport); sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X" - " %02X %08X:%08X %02X:%08lX %08X %5d %8d %ld %d %p", + " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p", i, src, srcp, dest, destp, sp->state, atomic_read(&sp->wmem_alloc), atomic_read(&sp->rmem_alloc), 0, 0L, 0, I don't know how to generate this kind of information in /proc, so I didn't test it.
I also looked the 2.4.18-rc1 and 2.5.5-pre1 kernels and the bug still exist.
-- Arnaud
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