From dfe5084ab81cdc9ef74093f3af395cb5688e793c Mon Sep 17 00:00:00 2001 From: Jonathan Blanchard Date: Tue, 10 Feb 2026 09:31:41 -0500 Subject: [PATCH] Fixed potential file system corruption when truncating or overwriting file data with fault tolerant mode enabled (#78) * _fx_fault_tolerant_cleanup_FAT_chain(): Add checks to prevent starting a new cluster deletion session in some corner cases where the end of the chain is reached. * Fixed formatting of previous commit. --- common/src/fx_fault_tolerant_cleanup_FAT_chain.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/common/src/fx_fault_tolerant_cleanup_FAT_chain.c b/common/src/fx_fault_tolerant_cleanup_FAT_chain.c index 9929ae9..ebd8176 100644 --- a/common/src/fx_fault_tolerant_cleanup_FAT_chain.c +++ b/common/src/fx_fault_tolerant_cleanup_FAT_chain.c @@ -207,7 +207,7 @@ ULONG last_FAT_sector; /* At this point, the head_cluster points to the cluster chain that is to be removed. */ - /* Tail cluster points to the back of the origianal FAT chain where the new chain is attached to. + /* Tail cluster points to the back of the original FAT chain where the new chain is attached to. The remove process terminates once this cluster is encountered. */ tail_cluster = _fx_utility_32_unsigned_read((UCHAR *)&FAT_chain -> fx_fault_tolerant_FAT_chain_insertion_back); @@ -262,7 +262,11 @@ ULONG last_FAT_sector; { if (head_cluster == next_session || next_session == FX_FREE_CLUSTER) { - next_session = next_cluster; + /* Do not start another session if this is the end of the chain. */ + if (next_cluster != tail_cluster) + { + next_session = next_cluster; + } } break; } @@ -277,7 +281,11 @@ ULONG last_FAT_sector; /* Get next session. */ if (cache_count == cache_max) { - next_session = next_cluster; + /* Do not start another session if this is the end of the chain. */ + if (next_cluster != tail_cluster) + { + next_session = next_cluster; + } } /* Update head cluster and next session into log file. */