Bodo Eggert wrote: > Warning: I'm only looking at the patch. > > You are supposed to print an error message for a user, not to write in a > chat window to a 1337 script kiddie. OK, you just matched the current style, > and your patch is IMHO OK for a quick security fix, but: > > - Security fixes should be CCed to the security mailing list, shouldn't they? > (It might be security@ or stable@, I'll remember tomorrow, but then I'd > forget to comment) > - Imagine you have three mounts containing a minix fs, how can you tell which > one is the the defective one? > - The message says "minix_bmap", while the patch suggests it's in > block_to_path. Therefore I asume "minix_bmap" to have only random > informational value. > - Does block < 0 or block > $size make a difference? > - the printk lacks the loglevel. > - Asuming minix supports error handling, shouldn't it do something? > > I'd suggest a message saying something like "minix: Bad block address on > device 08:15, needs fsck". > Ok, do you like this slightly better? It states the subsystem, the function with the error, the block nr. in the case of a too-large block, and the block device on which the error occurred. Honestly minix.fsck doesn't handle the situation well either, so at this point I hesitate to recommend it in the print. :) -------------------------- This attempts to address CVE-2006-6058 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-6058 first reported at http://projects.info-pull.com/mokb/MOKB-17-11-2006.html Essentially a corrupted minix dir inode reporting a very large i_size will loop for a very long time in minix_readdir, minix_find_entry, etc, because on EIO they just move on to try the next page. This is under the BKL, printk-storming as well. This can lock up the machine for a very long time. Simply ratelimiting the printks gets things back under control. Make the message a bit more informative while we're here. Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx> Index: linux-2.6.22-rc4/fs/minix/itree_v1.c =================================================================== --- linux-2.6.22-rc4.orig/fs/minix/itree_v1.c +++ linux-2.6.22-rc4/fs/minix/itree_v1.c @@ -23,11 +23,16 @@ static inline block_t *i_data(struct ino static int block_to_path(struct inode * inode, long block, int offsets[DEPTH]) { int n = 0; + char b[BDEVNAME_SIZE]; if (block < 0) { - printk("minix_bmap: block<0\n"); + printk("MINIX-fs: block_to_path: block %ld < 0 on dev %s\n", + block, bdevname(inode->i_sb->s_bdev, b)); } else if (block >= (minix_sb(inode->i_sb)->s_max_size/BLOCK_SIZE)) { - printk("minix_bmap: block>big\n"); + if (printk_ratelimit()) + printk("MINIX-fs: block_to_path: " + "block %ld too big on dev %s\n", + block, bdevname(inode->i_sb->s_bdev, b)); } else if (block < 7) { offsets[n++] = block; } else if ((block -= 7) < 512) { Index: linux-2.6.22-rc4/fs/minix/itree_v2.c =================================================================== --- linux-2.6.22-rc4.orig/fs/minix/itree_v2.c +++ linux-2.6.22-rc4/fs/minix/itree_v2.c @@ -23,12 +23,17 @@ static inline block_t *i_data(struct ino static int block_to_path(struct inode * inode, long block, int offsets[DEPTH]) { int n = 0; + char b[BDEVNAME_SIZE]; struct super_block *sb = inode->i_sb; if (block < 0) { - printk("minix_bmap: block<0\n"); + printk("MINIX-fs: block_to_path: block %ld < 0 on dev %s\n", + block, bdevname(sb->s_bdev, b)); } else if (block >= (minix_sb(inode->i_sb)->s_max_size/sb->s_blocksize)) { - printk("minix_bmap: block>big\n"); + if (printk_ratelimit()) + printk("MINIX-fs: block_to_path: " + "block %ld too big on dev %s\n", + block, bdevname(sb->s_bdev, b)); } else if (block < 7) { offsets[n++] = block; } else if ((block -= 7) < 256) { - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
