alsa-project/alsa-utils issue #231 was opened from cascades-sjtu:
Hi, I'm currently trying to use the static analysis tool [Infer](https://fbinfer.com) to find uncatched API-misuse bugs in OpenWrt packages, and I find a potential Integer Overflow in your project, version 1.2.9.
The bug located in aplay/aplay.c. Firstly, the program tries to write the remains bytes in `audiobuf` with the length of `loaded` in line 2865, and `loaded` is later used as the parameter for `safe_read` in the loop, then `loaded` is used as the 2nd argument of `pct_write()` and finally after a multiply operation, it is used as the size of Malloc in `remap_data()`, as shown in the following code:
```cpp static void playback_go(int fd, size_t loaded, off_t count, int rtype, char *name) { int l, r; off_t written = 0; off_t c;
header(rtype, name); set_params();
while (loaded > chunk_bytes && written < count && !in_aborting) { if (pcm_write(audiobuf + written, chunk_size) <= 0) return; written += chunk_bytes; loaded -= chunk_bytes; } if (written > 0 && loaded > 0) memmove(audiobuf, audiobuf + written, loaded);
l = loaded; while (written < count && !in_aborting) { do { c = count - written; if (c > chunk_bytes) c = chunk_bytes;
/* c < l, there is more data loaded * then we actually need to write */ if (c < l) l = c;
c -= l;
if (c == 0) break; r = safe_read(fd, audiobuf + l, c); if (r < 0) { perror(name); prg_exit(EXIT_FAILURE); } fdcount += r; if (r == 0) break; l += r; } while ((size_t)l < chunk_bytes); l = l * 8 / bits_per_frame; r = pcm_write(audiobuf, l); if (r != l) break; r = r * bits_per_frame / 8; written += r; l = 0; } if (!in_aborting) { snd_pcm_nonblock(handle, 0); snd_pcm_drain(handle); snd_pcm_nonblock(handle, nonblock); } }
# in remap_data() chunk_bytes = count * bits_per_frame / 8; if (tmp_size < chunk_bytes) { free(tmp); tmp = malloc(chunk_bytes); if (!tmp) { error(_("not enough memory")); exit(1); } tmp_size = count; } ```
The parameter passed to Malloc may be overflowed so that the actual allocated memory is small.
I also attached the analysis trace given by Infer FYI:
```json "trace": [ { "file": "aplay/aplay.c", "line": 940, "col": 14, "feature": [ "Input", "read" ] }, { "file": "aplay/aplay.c", "line": 940, "col": 14, "feature": [ "Input", "read" ] }, { "file": "aplay/aplay.c", "line": 2865, "col": 21, "feature": [ "Prune", [ "UnOp", "!", [ "BinOp", ">", [ "Var" ], [ "Cast", [ "Unsupported" ], [ "Const", [ "Cint", 0 ] ] ] ] ] ] }, { "file": "aplay/aplay.c", "line": 2868, "col": 2, "feature": [ "Store", [ "Var" ], [ "Var" ] ] }, { "file": "aplay/aplay.c", "line": 2878, "col": 8, "feature": [ "Prune", [ "UnOp", "!", [ "BinOp", "<", [ "Var" ], [ "Var" ] ] ] ] }, { "file": "aplay/aplay.c", "line": 2871, "col": 4, "feature": [ "Store", [ "Var" ], [ "BinOp", "-", [ "Var" ], [ "Var" ] ] ] }, { "file": "aplay/aplay.c", "line": 2872, "col": 8, "feature": [ "Prune", [ "UnOp", "!", [ "BinOp", ">", [ "Cast", [ "Unsupported" ], [ "Var" ] ], [ "Var" ] ] ] ] }, { "file": "aplay/aplay.c", "line": 2878, "col": 8, "feature": [ "Prune", [ "BinOp", "<", [ "Var" ], [ "Var" ] ] ] }, { "file": "aplay/aplay.c", "line": 2879, "col": 5, "feature": [ "Store", [ "Var" ], [ "Var" ] ] }, { "file": "aplay/aplay.c", "line": 2899, "col": 3, "feature": [ "Store", [ "Var" ], [ "BinOp", "/", [ "BinOp", "*", [ "Cast", [ "Unsupported" ], [ "Var" ] ], [ "Var" ] ], [ "Cast", [ "Unsupported" ], [ "Const", [ "Cint", 8 ] ] ] ] ] }, { "file": "aplay/aplay.c", "line": 2900, "col": 3, "feature": [ "Store", [ "Var" ], [ "BinOp", "+", [ "Var" ], [ "Var" ] ] ] }, { "file": "aplay/aplay.c", "line": 2871, "col": 4, "feature": [ "Store", [ "Var" ], [ "BinOp", "-", [ "Var" ], [ "Var" ] ] ] }, { "file": "aplay/aplay.c", "line": 2872, "col": 8, "feature": [ "Prune", [ "UnOp", "!", [ "BinOp", ">", [ "Cast", [ "Unsupported" ], [ "Var" ] ], [ "Var" ] ] ] ] }, { "file": "aplay/aplay.c", "line": 2878, "col": 8, "feature": [ "Prune", [ "BinOp", "<", [ "Var" ], [ "Var" ] ] ] }, { "file": "aplay/aplay.c", "line": 2879, "col": 5, "feature": [ "Store", [ "Var" ], [ "Var" ] ] }, { "file": "aplay/aplay.c", "line": 2895, "col": 3, "feature": [ "Store", [ "Var" ], [ "BinOp", "/", [ "Cast", [ "Unsupported" ], [ "BinOp", "*", [ "Var" ], [ "Const", [ "Cint", 8 ] ] ] ], [ "Var" ] ] ] }, { "file": "aplay/aplay.c", "line": 2896, "col": 7, "feature": [ "Call", "pcm_write" ] }, { "file": "aplay/aplay.c", "line": 2126, "col": 6, "feature": [ "Prune", [ "UnOp", "!", [ "BinOp", "<", [ "Var" ], [ "Var" ] ] ] ] }, { "file": "aplay/aplay.c", "line": 2130, "col": 9, "feature": [ "Call", "remap_data" ] }, { "file": "aplay/aplay.c", "line": 2069, "col": 2, "feature": [ "Store", [ "Var" ], [ "BinOp", "/", [ "BinOp", "*", [ "Var" ], [ "Var" ] ], [ "Cast", [ "Unsupported" ], [ "Const", [ "Cint", 8 ] ] ] ] ] }, { "file": "aplay/aplay.c", "line": 2070, "col": 6, "feature": [ "Prune", [ "BinOp", "<", [ "Var" ], [ "Var" ] ] ] }, { "file": "aplay/aplay.c", "line": 2072, "col": 9, "feature": [ "IntOverflow", "malloc", [ "Var" ] ] } ], ```
Issue URL : https://github.com/alsa-project/alsa-utils/issues/231 Repository URL: https://github.com/alsa-project/alsa-utils