In the Linux kernel, the following vulnerability has been resolved: sysv: don’t call sb_bread() with pointers_lock held syzbot is reporting sleep in atomic context in SysV filesystem [1], for sb_bread() is called with rw_spinlock held. A “write_lock(&pointers_lock) => read_lock(&pointers_lock) deadlock” bug and a “sb_bread() with write_lock(&pointers_lock)” bug were introduced by “Replace BKL for chain locking with sysvfs-private rwlock” in Linux 2.5.12. Then, “[PATCH] err1-40: sysvfs locking fix” in Linux 2.6.8 fixed the former bug by moving pointers_lock lock to the callers, but instead introduced a “sb_bread() with read_lock(&pointers_lock)” bug (which made this problem easier to hit). Al Viro suggested that why not to do like get_branch()/get_block()/ find_shared() in Minix filesystem does. And doing like that is almost a revert of “[PATCH] err1-40: sysvfs locking fix” except that get_branch() from with find_shared() is called without write_lock(&pointers_lock).
OS | Version | Architecture | Package | Version | Filename |
---|---|---|---|---|---|
Debian | 12 | all | linux | < 6.1.90-1 | linux_6.1.90-1_all.deb |
Debian | 11 | all | linux | < 5.10.216-1 | linux_5.10.216-1_all.deb |
Debian | 999 | all | linux | < 6.8.9-1 | linux_6.8.9-1_all.deb |
Debian | 13 | all | linux | < 6.8.9-1 | linux_6.8.9-1_all.deb |