diff options
| author | Heather McIntyre <[email protected]> | 2024-07-12 18:28:13 -0400 |
|---|---|---|
| committer | Aaron Merey <[email protected]> | 2024-08-20 17:13:01 -0400 |
| commit | f3de289b5081bdcea6f867f1d87f006daf5a02ce (patch) | |
| tree | 6e6d2fe35eba3ec1c27772299f3a5e9688b1d7e0 /libelf | |
| parent | 17bb644d9adf16283d34243b0c2a0aba94b64dba (diff) | |
libelf: Fix deadlock in __libelf_readall
Apply locking during __libelf_readall.
Signed-off-by: Heather S. McIntyre <[email protected]>
Signed-off-by: Aaron Merey <[email protected]>
Signed-off-by: Mark Wielaard <[email protected]>
Diffstat (limited to 'libelf')
| -rw-r--r-- | libelf/common.h | 24 | ||||
| -rw-r--r-- | libelf/elf_readall.c | 4 |
2 files changed, 16 insertions, 12 deletions
diff --git a/libelf/common.h b/libelf/common.h index 9b2a856d..8e33a70e 100644 --- a/libelf/common.h +++ b/libelf/common.h @@ -89,30 +89,34 @@ allocate_elf (int fildes, void *map_address, int64_t offset, size_t maxsize, } -/* Acquire lock for the descriptor and all children. */ +/* Caller must hold a lock for ELF. If there are children then a lock + will be acquired for each of them (recursively). */ static void __attribute__ ((unused)) -libelf_acquire_all (Elf *elf) +libelf_acquire_all_children (Elf *elf) { - rwlock_wrlock (elf->lock); - if (elf->kind == ELF_K_AR) { Elf *child = elf->state.ar.children; while (child != NULL) { + rwlock_wrlock (child->lock); + if (child->ref_count != 0) - libelf_acquire_all (child); + libelf_acquire_all_children (child); + child = child->next; } } } -/* Release own lock and those of the children. */ + +/* Caller must hold a lock for ELF. If there are children then a lock + will be released for each of them (recursively). */ static void __attribute__ ((unused)) -libelf_release_all (Elf *elf) +libelf_release_all_children (Elf *elf) { if (elf->kind == ELF_K_AR) { @@ -121,12 +125,12 @@ libelf_release_all (Elf *elf) while (child != NULL) { if (child->ref_count != 0) - libelf_release_all (child); + libelf_release_all_children (child); + + rwlock_unlock (child->lock); child = child->next; } } - - rwlock_unlock (elf->lock); } diff --git a/libelf/elf_readall.c b/libelf/elf_readall.c index d0f9a28c..4ef8fe97 100644 --- a/libelf/elf_readall.c +++ b/libelf/elf_readall.c @@ -84,7 +84,7 @@ __libelf_readall (Elf *elf) /* If this is an archive and we have derived descriptors get the locks for all of them. */ - libelf_acquire_all (elf); + libelf_acquire_all_children (elf); if (elf->maximum_size == ~((size_t) 0)) { @@ -141,7 +141,7 @@ __libelf_readall (Elf *elf) __libelf_seterrno (ELF_E_NOMEM); /* Free the locks on the children. */ - libelf_release_all (elf); + libelf_release_all_children (elf); } rwlock_unlock (elf->lock); |