https://bugzilla.kernel.org/show_bug.cgi?id=114701 Navin Parakkal <navinp1912@xxxxxxxxx> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |navinp1912@xxxxxxxxx --- Comment #1 from Navin Parakkal <navinp1912@xxxxxxxxx> --- diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 50e05df..8ccfcf7 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -1278,6 +1278,8 @@ static int mb_find_order_for_block(struct ext4_buddy *e4b, int block) /* this block is part of buddy of order 'order' */ return order; } + if (order > e4b->bd_blkbits) + break; bb += 1 << (e4b->bd_blkbits - order); order++; } @@ -2616,6 +2618,8 @@ int ext4_mb_init(struct super_block *sb) do { sbi->s_mb_offsets[i] = offset; sbi->s_mb_maxs[i] = max; + if (i > sb->s_blocksize_bits) + break; offset += 1 << (sb->s_blocksize_bits - i); max = max >> 1; i++; The only case if when i>b you compute off and max but those are not assigned . So those values can be ignored. It keeps the old behaviour intact and fixes the undefined behaviour. offset += 1 << (sb->s_blocksize_bits - i); /* Remove the if to see trap error at runtime */ /* gcc -fsanitize=undefined x.c */ int main() { int i=1; int b=12; unsigned ub=12; unsigned off=0,uoff=0; do{ if(i> b) break; off+=1<<(b-i); uoff+=1<<(ub-i); i++; } while(i<=b+1); } -- You are receiving this mail because: You are watching the assignee of the bug. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
